The game always loads an area of the main end island when the player is in a specific area near the main island. However, it still loads the area even though the player near the main island is in creative mode and creativePlayersLoadChunks is set to false.

It can be seen as a vanilla bug, because spectators also make some chunks loaded in the end when spectatorsGenerateChunks is set to false.
Also, it is said that "creative players do not load chunks like spectators with gamerule spectatorsGenerateChunks false when creativePlayersLoadChunks is set to false", which means this bug actually works as intended in a way.

My suggestion is that consider this as a bug.

This is not considered a bug because the rules work as expected. It's the dragon fight loading the main end island as long as there's a player present in the end. Rules specify the player will not load chunks, which they do not.
A better option would be a addition of rule like dragonFightLoadChunks but idk.

This is not considered a bug because the rules work as expected. It's the dragon fight loading the main end island as long as there's a player present in the end. Rules specify the player will not load chunks, which they do not. A better option would be a addition of rule like dragonFightLoadChunks but idk.

I see. Alright.