Well, look at Cobra Kai, for example. Somehow the creators managed to revived a dormant franchise with respectful treatment of its original characters while bringing new casts for modern vibes and making it work on a satisfying level for both the original & current fandom.
The main point here is respectful treatment of original, established characters. Also, the format of basically "5 hour movie broken down into 10 episodes" which is still digestible for the audiences.
All things considered, I'd think a grand finale of this format for all original, established characters (including Michael with bigger deuteragonist role) would serve this franchise well enough.