I've been thinking exactly the same thing. It makes a lot of sense with our current squad. Both full backs are going to bomb on, and Wirtz won't do the defensive work that Szoboszlai did in that role, so we need three "proper" midfielders in there with Wirtz ahead of them. The only way to do that, really, is a 4-1-2-1-2.
If that's the case, I think it makes the need for a proper DM even more important. Otherwise we're looking at Grav, Macca, Jones, Endo, Dom and (possibly) Elliott for the midfield roles. And Grav aside, I don't want to see any of them at DM for too long.