OK, let's go point by point on this, because I think you are ignoring whole aspects of reality, and this leads you to erroneous conclusions.
First, some factual claims:
Roberto wants to be paid handsomely on longer years if he takes pay cut now.
Where did you read this?
Busquets will accept something way less than the club willing to offer.
And this?
Then, the core of your thought is one-dimensional on this:
No, it is just not important actually.
-Messi isn't under contract, if he wants to stay here, he can take a pay cut, if he doesn't he won't stay.
-If he wants to leave, he can choose to leave on his own terms.
So absolutely no comparison between both cases.
That is why I rightfully ignored it.
You are assuming that what is important is whether "under contract/under no contract", without taking into consideration the context.
Messi isn't just any player, who happens to be under contract.
He is up there with the Barca Legends, maybe on the top of the list.
Everybody knows how much he was getting paid on his last contract,
everybody knows how much PSG and City were willing to pay him,
everybody knows no one has 'earned it' more than him to get paid more than anyone else in the squad.
So, just by Messi renewing with 50% cut, the signal is sent to everyone else under contract.
And this is where you don't make sense:
You are counting on peer pressure as the biggest leverage of the club
Some players might do that, but they have family and agents who has zero incentive to do it. You think a player agent will happily accept a lower pay day for himself because his client decided to give a pay cut to a billion dollar organization? You think their wives/GF will happily convince them to stay here for lower money? Because Messi accepted to be the best paid player on the team? or because the guy whose GF is wealthier than any other footballer (except Messi and CR7) has accepted a pay cut?
And for 3rd time, all of those are players tied for long period to the club, they have ambitious about being Barca coach/president, what does Griezmann trading for now?
The only other players who accepted such pay cut, accepted a longer contracts on high wage later, just in case you think you can make another comparison.
And here we get to the crucial point:
Squads are not just a conglomerate of athletes under contract. Maybe that's just a way to see this, but it's very far from reality.
Squads are communities with hierarchy and status.
In the Barca squad, Messi -who renewed with a 50% cut - is on the top of that hierarchy.
In the Barca squad, Pique - who publicly agreed to the cut - is very high on the hierarchy.
In the Barca squad again, Griezman is quite low on the hierarchy.
There are many reasons for that (like that he hasn't performed, he is not Barca-bred, he does not fit in with Messi, and many others), but that's the harsh truth.
Hence, that gives you that factor you are trying to totally overlook.
Griezman's position in not determined only by his contract.
Because the situation is not only legal, but there is 'real life' power dynamics involved, as I have written many times.
Griezman's position in the hierarchy of the squad weakens a lot his position on the issue.
He can't (not legally, but in real life) be getting paid more than Messi. This will never happen, mark my words.
He can't (not legally, but in real life) be getting the same wage, when all Barca heavyweights have agreed to 50% or more pay-cut.
Because his status in the squad can never allow him that.
When Laporta said 'pay-cuts or there is no club', Griezman knows very well that *IF* (that IF is important here) he is gonna still be a Barca player next season, he will adjust like everyone else.
And it's really irrelevant how his personal reasons (wife/GF, desired place of residence) factor in here, that's something he himself considers of course for his own benefit, but the club and his teammates do not give a fuck about that.
By the way, without realizing, you stated another reason why the Catalan-bred will agree to the pay-cut in 0 time.
Let's get our facts right:
A-No club that respect itself will bench a player like Griezmann for financial reasons.
B-Griezmann can sit next year and force the club to do what he wants next summer, it isn't like it hasn't been done before.
Stubbornness isn't a way to do business, you don't flush 30-45M per year in the toilet to feel powerful. Laporta is a politician and he knows that.
Unless an EPL comes with a lucrative offer for Griezmann, the club has no ground to punish him, and in fact he will have a stronger case in court against the club if we bench him.
A) is simply and plainly false.
Look what the club told clearly and loudly Dembele about his renewal.
Same will be said to Griezman if no transfer is possible nearing the end of the summer window.
Because Laporta ain't no Barto, and he is not bluffing here. He knows what to do, and as in his first tenure he got rid of the old guard by releasing players and cutting wages, he is gonna do it again. With Messi agreeing to 50% cut, and Pique and co following suit, he is never gonna budge with a player who is low in the pecking order of the squad.
That's about whether club can sit him on the stands. Of course it can!
If we get to this point and Griezman cannot get transfered out by the end of the window, and mark my words here, he will agree to whatever pay-cut is necessary along the likes of the rest of the squad.
Because, he will never risk his
i) fitness-form
ii) image
iii) reputation
iv) future career
for the sake of his current wages.
That's not his personality to begin with, and most importantly,
I repeat again, this can be done ONLY by players who have NOTHING to lose (a.ka. Bale or Umtiti for different reasons) no future career, do not care about their image and reputation.
So the only thing left is their paycheck.
B)
That's wrong as well.
If Griezman chooses to sit on the contract and not play (which he will never do as explained above), the only thing he will gain (apart from the money)
will be the power to fully determine his next club.
But, hey! Would there be any after him with 2 years on the stands? Even Atletico will change their minds.
LEt alone France NT and the WC.
Never happening in a million years. He is not that dumb/parasite.
PS: Finally, you take the leaks from his entourage word for word as facts about what will happen.
Whereas they are really
part of the diplomatic play going on between him and the club.
As I wrote above,
he knows his status in the hierarchy is low,
he knows he is expendable,
he knows that he will never get paid at Barca more than Messi in any possible world,
So he is playing his cards, using the contract in force as his weapon to gain something.
And that something is getting the move he wishes (Atleti)