How about we look at this glass half full. In normal finances this is a completely logical move. Buy a prospect early ahead of the rest of Europe, and then loan him out for development. It is just that our media and Xavi leaks made this shit worse than it ever had to be.
He now has a platform to adapt to the league and play in a team that has a similar setup to us. If he has a successful season then we can either bring him back or sell him for more than the Sporting deal. Sporting knew what they were doing.
The only problem with LaLiga is guys like Dovbryk and Sorloth score 20+ goals and only sell for 30m because of BO clauses and overachieving. While in Porkchop Evanilson scores 13 goals in 27 and goes for 37m.
But with Vitor age, Brazil tax, low salary mass and high BO, we may actually benefit hugely from this move.
Not only glass half full but I think this is actually the correct way to look at it.
He's a very young player and it doesn't make sense to instantly sell him after we've spent a season trashing him in the media, as his stock is at its lowest. He clearly has talent and I think he could plausibly score around 13-15 LaLiga goals in a season as a starter.
If anything, the decision to loan him is low risk and possibly massive reward.
Worst case : he flops and we can still probably find a team to pay 20m euros for him.
Best case : he scores 15+ goals (not that unlikely in my opinion) and his value skyrockets.
Selling him now would be the worst business decision in my opinion. I think this is a good decision by the club and we won't regret it.