I'm really not sure we'd be willing to pay in excess of £100m for a player with one year left on his contract. One bad injury and you're left looking very silly - see Mount at the rags.
Musiala is a generational talent, no doubt. But I'm not sure he's what we need. I don't see Kevin leaving next summer, and I'm doubtful that Bernardo will either (much more likely that he leaves on a free in 2026 IMO).
You have to assume that the plan is for Foden to take up the mantle through the middle. So that leaves us with Foden, KDB, Gundo, and probably Bernardo. Also, McAtee, Echeverri, Lewis, Bobb, Grealish, O'Reilly... and there's the very real possibility that Nunes kicks on this season too and secures his long-term future. Basically, we're not exactly short in those central attacking areas.
That's not to say we won't sign someone if Bernardo leaves. But I don't think it'll be Musiala. Probably someone who can play deeper and compliments KDB/Foden more, like a Wharton type.