Firstly I just want to say that I'm gay and I HATE when a character is reduced to just their sexuality. It's uncreative and incredibly boring when a gay character is just there to be the 'token' gay. However, I definitely don't see Neeko like this, but it seems that many people do.
In Neeko's interactions she has like what, 10 lines max that show her crushing on other female champs? I don't understand how people think that's 'too much' and 'reducing her to her sexuality'. It's not as if she's running around screaming 'I'm a lesbian!'. I think it's cute how Riot have portrayed her attraction to some of the female champions without making it overwhelming.
Secondly I've seen people take issue with Neeko's creator saying that she 'identifies as a lesbian'. I don't think the creator meant that Neeko would be the type to actually say 'Hey everyone, I'm a lesbian', but simply that she's just attracted to girls.
I hate how as soon as Riot make a character that's canonically gay people accuse of them of catering to SJWs and getting too political. When Varus' lore was changed one of the major complaints was that Riot should've added a new champion if they wanted a gay character.. well that's what they've done and people are still accusing of them of doing it just for diversity. Gay people actually do exist irl, and in a game with 140+ champs what's wrong with 1 lesbian? People don't complain about Xayah and Rakan rubbing their relationship in everyone's faces, but suddenly when a girl champion makes cute remarks and crushes on other girl champions people accuse Riot of pandering..? I just don't understand.