Still waiting on Kawhi, but so far the Bucks would likely be #2 in the East in terms of betting.
The Sixers lost Butler and Redick, but gained Horford and Josh Richardson. That is going to be a really good defensive team. Redick was the weak link on that end and now they can run out Embiid, Simmons, Horford, T. Harris, and Josh Richardson. If Embiid can stay healthy (a huge if), they have to be considered the favorites in the East.
The Bucks lose Brogdon and Mirotic. Mirotic is a guy who is unplayable in the playoffs. They were 25-9 overall (playoffs and regular season) without Brogdon, but his loss still hurts. However, Hill is as good a defender and is a 38% career shooter from 3. If DD improves from his rookie year, they'll be fine there. There is probably another move or two coming with a MLE. That's the key. Who else can the Bucks get to come in and chase a ring? Giannis, Middleton, Bledsoe, Lopez, G. Hill, DD, Ilyasova, Connaugton, and S. Brown are in the rotation now. I still think they need another big guy that can soak up 15-20 minutes.
The Celtics don't scare me at all right now. Kemba Walker for Kyrie Irving and Rozier is a net loss. Losing Horford to the Sixers is a killer for them. Maybe they have another move coming, but they have gotten worse so far.
With Durant out all year, if Kawhi bolts to LA, the East probably comes down to the Bucks and Sixers depending on who stays healthy.