With griezzmann its a win win for us. Suarez doesn't need to be permananently benched but we can rotate both and slowly start phasing out suarez till griezz takes over.
Yes, I really hope this happens - it would help our attack very much.
I hope if he does come this means this is the end of Suarez being a full blown starter and a good lesson to players like Suarez, just because what you did several seasons ago was incredible it doesn't mean you should still be a full blown starter as his performances have decayed heavily.
In a realistic world that is my hope. We simply cannot sacrifice our one talented winger, so we can shoe horn in a declining Suarez all because the club and the coach don't seem to have it in them to tell him that his performances in the past year have been holding us back.
This is very important as well, as you say: Griezmann and Suarez should replace each other, not take up Dembeles playingtime, as he obviously would benefit the team very much if he is integrated. And there is nothing talking against Dembele being played with one or the other up front, as I see it.
Griezmann/Suarez --- Dembele
--------------Messi---------------
-----Coutinho---Rakitic/Roberto
-----------Busquets--------------
That would be a great lineup, imo, for next season. Of course we could need another backup in midfield other than Arthur who only arrives in January, and other than Denis/Paulinho/Alena, all of whom can't make a difference if we get injuries.