It will if they let him sell who he wants. I can see it being difficult for both Mkh and Ozil to play his football, and expect that only one will truly fit. Discipline and defensive commitment are 1000% required. Mustafi could become a much better player this way. As a manager, I like him, but they need to bring a different balance to their team than what they have now. The budget also becomes a problem because they need pace out wide, which is currently extremely expensive. Those wide players also need to be quite committed, the fullbacks balanced, the midfielders big and disciplined. Inevitably he will do something people won't like. I also don't see him sticking with both Lacazette and Auba, but it's very tough to know which. The forwards he had at Sevilla are more like Lacazette. Auba could be moved wide in order to save money.
I'm pretty much going to disregard what he did at PSG because I don't think it matters what he did with a team who had an unlimited budget. When he doesn't have an unlimited budget, that's how his teams work. He also played with a double pivot, so Arsenal will need another #6. Might be first on the list.
Mustafi definitely wanted out during the January window and played absolutely atrocious in the final third of the season. He might have decent talent, but he needs to be gone when the season starts.
Chambers has also been a disaster and might want more playing time, so don't be surprised if he moves to a championship squad in this window as well. I think the Lichtsteiner signing, which is on the verge of being complete tells you that Arsenal do not have faith in other players to fill that role such as Holding and Calum.
Arsenal have always rumoured to be in the market for a winger to play on the opposite side of Sanchez and Lacazette. Being linked with Forsberg is not a surprise by any means for me. He isn't needed, but with a new manager some players are definitely going out (and others in) just due to differences in philosophy. Sven brought in Mkhi, even over Martial who Wenger wanted, hard to see him sell him considering how much power he has in the organization already. But it is a very realistic possibility that he's gone. Getting 30 million for him increases our budget to 100 million which wouldn't be too shabby.
You're right though that Emery is a high demanding manager and even though Mkhi showed that his defencive side is quite underrated when he was put on the wing, his work rate still isn't the best on the team.
I would be surprised if he didn't start a duo of Auba on the wing, Laca in the middle, and Ozil in the middle and just put up with the defencive shortcomings of those players. They looked amazing to finish the season and considering the money that Arsenal have invested in them. The biggest question marks for me is in the midfield and how he arranges the formation with Ozil, Mkhi, and Ramsey. A lot of uncertainty and I can see him want to change this portion of the squad the most even with the shortcomings in goal and on the backline. That is why I think Seri is absolutely a player that Emery would kill to have. Another player who I think he will love as well is Danny Welbeck, just gotta stay healthy.