I don't think Barcelona will be after Griezmann anymore, not after he turned down the offer from last summer, not after he's been booed this last game by barcelona fans, and not after Dembele and Malcom seem too slowly adapt to the clubs unique style. Although one could argue that Dembele is injured a lot and Malcom still needs to progress more, but both are really young and could reach Griezmann's level.
Back to Atletico, Simeone is the best payed coach in the world and he did wonders with a relatively small club, but i would dare to say that right now, Atletico is no longer a small club and everyone expects more from the club, especially in regards to the play style.
I mean it's ok to play like that against big clubs, but they use the same style against small spanish clubs which costs them a lot of points this championship.
I would also add that, in my opinion, it's Simeone's fault that Atletico lost 3-0 against Juventus and not Juve's merit.
In conclusion, i would expect some changes this summer for Atletico.