The last new services I’ve noticed being added were Disney+ and Disney+ Hotstar, soon after they started carrying K-dramas.
Whatever the reasons are, it seems that, after an initial flurry of even obscure services that users suggested being added, the only reason another service will added is if a new AAA-type K-drama is exclusive to it. So I’ve just made do with adding missing links to services already approved, for now (of which there are, admittedly, a lot to add, especially for Apple TV).