Just a theory on what happened, but sampling is almost always not fair use (https://en.wikipedia.org/wiki/Sampling_(music)#Legal_and_eth...), and I see many indie labels publishing music with sampling in them. Regardless of your opinion here, it would make YouTube in the clear.
a brief look at a few random tracks on their bandcamp site doesn't show any sampling. if they have videos that use sampling, then those videos should be taken down, not the whole channel.
I wish I had a link for you but it’s a relatively common thing to have TV shows and movies sampled in lofi tracks. I’ve heard clips from anything between “Talladega Nights” to “10 Things I Hate About You”.