A genre is defined by a set of stylistic similarities and it's logical that someone who likes one artist/band of a genre will be more likely to like another artist from the same genre. But although the correlation is probably high, there are plenty of reasons that a listener might not like a similar band. Maybe the band plays badly, or the singer has an unpleasant voice, or the guitarist plays boring solos, or the texts are uninteresting, or the sound is badly mixed, or whatever. So even though it's likely you'll like something similar, there's no guarantee. Music tastes are just too subjective.
The algorithms of streaming services like Spotify work this way. If you like one song, the service suggests other songs that are similar.
So, to answer your question: there is probably a significant overlap between Taylor Swift and Adele fans (and probably only a small group of hard-core fans of each of them who hate the other one just because they're not their idol).
Unfortunately I don't know of any studies which would substantiate this.