Griezman had a bit of a revival this past season. He's probably the only one with a high salary that will most certainly be sold.
Dembele and Coutinho on the other hand are uncompletely unsellable.
I'll think they'll line up something like this next season:
Messi
Memphis Pedri Fati
De Jong Busquets
Alba Araujo Garcia Mingueza
Ter Stegen
No way Memphis/Aguero will do what Griezman did and track Messi's man for him if Messi is RW. Guy just has to play centrally.
Vs weaker teams: Messi no 10, Aguero/Memphis up top, Pedri/Memphis LW, defending in 4-4-2.
Pique and Dest will come in for 5-3-2.
They'll try to get rid of Umtiti and Lenglet and the Spanish FA will let them off the hook.