Ruvika: I think you are taking this too seriously, I know everything is political, but I don't know if they are doing this with the intention of "convert" someone or make them gays, it's something like "here we have some games if you are LGBT+ that maybe you will find some representation or themes that you may found interesting".
It's likely more the fact that a number of companies(GOG included, albeit to a lesser extent) often put the same old pride logos/events up every June(and at other times as well) to gather more sales from people who think/reason "Oh, x company really supports LGBT...better spend some more money there!"
Essentially, many companies treat people(LGBT/etc) like gullible walking wallets, and some of us dislike being treated as such.