Outlets always censor themselves and always did. Where to draw the line is obviously up to each outlet. A record store might be able to sell the rap songs about killing cops because they are confident that they can be seen as offering a wide selection and not merely promoting violence. A record store that only sold that kind of music should rightly be questioned about their motives.

Radio stations are more careful about music selection than record stores, because they are seen as choosing their music making it an expression of their opinion and not their customers. They play it next to messages from sponsors who don't want to be associated with everything and so on. Spotify is obviously closer to record store than radio station, but they do have commercial messages.

(A note for younger readers, a "record store" was a kind of brick and mortar shop where songs were sold engraved onto physical artifacts).

But (and this I think is key): Even record stores have always entirely stayed away from some material. Not just the material that is illegal, but also material that is simply offensive or objectionable. They put Parental Advisory stickers on rap albums, but no main street record stores carried nazi music, for example, even though there was never a shortage of it, and it was never outlawed in many countries. If a band was known as a nazi music band, they weren't showing up on record store shelves with their non-nazi album either. That is - they were boycotted as artists, not merely some objectionable content. I'd put Alex Jones (but not many more of JRE guests) in the "Nazi band" bucket. The ones that record stores didn't have on shelves because customers, owners, employees etc wouldn't stand for it.

My point is: this isn't some "woke" phenomenon of cancel culture. It's the way it's always been.