>>34128378I think this is one of those things were gamefreak came up with a concept in a way and stuck with it forever.
Being called flying made sense in a time like gen 1 because everything with the typing was literally a bird or similar animal with wings that could fly, except maybe doduo/dodrio but those are implied to have meme flying abilities. It was exclusively a secondary typing and never put as a mon's only type, so it could be seen more as a quality of a mon in addition to its primary type. Charizard is a fire mon that flies, pidgeot is a normal mon that flies, etc.
In top of that, it could be argued that "wind" was just the special category within flying moves, similar to how "sound" comprises a huge part of the special category within normal moves.
TL-DR; Gamefreak did what they always do, they stick to the way they created it for an autistically long period of time until they are confronted with a pattern breaker, in this case, the embodiment of wind, tornadus. After that, we've seen our first primary flying type line, but the name of the type will never be changed.
