I appreciate McTominay, his athletic qualities and mindset. The problem I see with him (and probably what motivated his potential exit last summer) is the fact that he doesn't fully fit in any role in the current midfield. I see him as a good complementary player in a midfield three, next to a creative 8 who can orchestrate, and both backed by an actual anchor. He could do a bit of everything there while the team remains balanced.
Our problem as always is how we combine the pieces we have in the squad. If we take Bruno as a reference as a number 10, the two midfielders should be someone dictating the play from behind (EtH wanted De Jong) and a strong defensive presence next to him who can also manage the ball well when pressed.
From that point I don't see how we can fit McTominay into that setup when he's not solid enough as an anchor, he's not a deep playmaker nor a creative number 10.
Playing him in a midfield two and instructing him to bomb forward leaves the team too open defensive wise. Taking Bruno as a reference any combination of two out of Casemiro-Amrabat-Mainoo makes more sense than McTominay. Even under a new manager I think the story would be the same. I don't think it's about ten Hag but about combining the players we have.
It was the same with Fred. Next to Casemiro we're too stiff, there's no "football" (as EtH said once after subbing Casemiro). Next to Eriksen we're not solid enough. There's no good combination with these 'supportive' kind of midfielders. Both together (Scott and Fred) did a job under Ole but it was never going to be the formula going forward.
If I was Scott I'd be looking for a team where his qualities could be properly exploited. There's a good player there in the right setup but he'll remain "a square peg" here and never looking fully convincing in any role. As I said he doesn't disturb me in the squad, good emergency option to chase a late goal maybe and playing the occasional game. But it could be beneficial for both sides to explore new options next summer.