Bass slut lyrics are implicits;
I'm Down with Brown Town drops f word once, that's all;
NASA have a bit more explicit lyrics, but the song is just using the word as an expression, song isn't about sex (or at least I think, definetly not explicit at least).
Aka, ura exemples aren't the same at all as Krystal's song. The song aims for sexual intents.
https://osu.ppy.sh/help/wiki/Rules/Song_Content_Rules#mapping-tracks-with-explicit-lyrics contains more information on the subject to help classifie what is acceptable or not. Imo this violate this rule. If you want full confirmation, ask directly a member of GMT (pm or the new website message thingy, which apparently now give notification)
Edit: once again I spent too much time typing, listening songs and seeking the correct links, Tic beat me up to it... well you got your gmt answer at least, case closed.