The characters being ancillary and easily edited out/cut is by design so they can still use the movies in foreign markets that are hostile to lgbt rights
If the gay character is only identified as gay in one scene where they say “I’m gay” or kiss for 10 seconds you can just cut that part out and still screen it in Saudi Arabia. Disney doesn’t actually give a shit about lgbt issues, they give a shit about what will sell
Thus a prominent main character who is gay or a movie about a character coming to terms with queer identity is far less likely because that basically means they instantly lose out on much of the lucrative international market
This is probably related to the neural systems for olfactory fatigue, eg why you stop noticing certain smells that are constantly present like your own body odor and the smell of your home/room
There’s a very good Wikipedia article that explains it much better than I can. But taste and smell are closely linked and the sensory systems become fatigued from overindulgence somewhat quickly. Conjecture but the massive amount of flavoring and sweetener in modern beverages is probably a factor in hastening this process