This movie still has issues because of story threads that are not tightly resolved. But if you ask me, Stallone never should have been involved to begin with as majorly as he did. The first CREED did not need to have him around so much and would have flowed better had he just had a glorified cameo and someone else who KNEW Rocky had trained Adonis instead and we had Rocky show up a couple times and that's it. Then Creed II could have given him something a bit bigger but not to the extent he is a main character, just to show audiences this is not about Rocky anymore nor is he an asset to THIS series.
Creed I and II relied too much on Rocky it became a worry if this series could even continue without him. But I'm glad now they made that move cutting him entirely and the movie is still getting some good reception. So going forward, they see they can do this without Stallone. Getting rid of Rocky was also good for the growth of Adonis to see how he handles things on his own as a character.