The main point that always is brought up is allowing gambling/slot streaming, but yeah what you said is more or less on point (gambling gets brought up because of it direct ties to the owners/sponsors/investors with such sites).

It just occurred me how it was usually done in reddit, you could advertise in related subs, for example !games@sh.itjust.works but it’s usually done with the permission of the mods of these subs.

It would be probably pretty similar if you just started a sub on reddit or any kind of forum I guess. It interest me in particular you community, but I’m not sure how it would be the best war to solve this in general, the newcommunities shared by @bdonvr@thelemmy.club seem like a great idea to advertise without annoying many people, probably will keep an eye on that.