I think the Raptors still will be good even presuming they lose Kawhi. That's a deep team. Their scouting department has found diamonds in the rough like Siakam and Van Vleet. They aren't going to replace Kawhi, but they still should be a major player in the East for at least another couple of years.
Obviously, Milwaukee becomes the team to beat. I think Brooklyn is well-positioned to take a big step up with its cap room coming off the season it had. Boston probably takes a step back. Miami COULD make a move forward. Sixers still should be good, although they've still got some big questions to be addressed and I have big doubts about their chemistry. Depending on what Atlanta does with its assets, the Hawks are a darkhorse that probably becomes a major force in two years.
But, yeah, I see the Raptors still being in contention for a top four seed in the East next year, Kawhi or not.