There's two issues. HG grown quota, which MGW is fine on, and pep's i'll quit if the squad is too big stance. Fans obviously want 25/26 players so find ways to convince themselves it won't matter. But squad size is clearly a massive, massive issue to pep. He tanked last season holding his ground over it, more or less.
If MGW comes in on top of cherki and Reijnders, I think basically all of Bernardo, Gundo and Kovacic would have to go. We have a million centre backs as well, bought for a system we're now abandoning as we purchase full backs. And the number of players/number of unhappy players is going to reach too many for pep.