But I think the motivation for "free speech maximalism", from the perspective of a tech platform, is more strategy than principle: if you're in a position to make a decision as to who or what to silence, you are going to be subject to constant pressure from all directions, rightly or wrongly. Sticking to your guns and enforcing a limited and specific scope (illegality, ToS violations) is a "bright line" policy. Holding to it consistently means not having to constantly justify and take heat for tough gray-area decisions, which is a losing game anyway, since you won't be able to appease everyone no matter what you do.
This is plainly censorship (within Spotify's rights, but still censorship) and while nobody's 1A rights have been violated, it's still affecting someone's ability to publish to their audience.
That's not a legal issue, but a moral one.
I think it's a very different situation, simply sharing your content on a platform, where I think free speech is much more relevant, vs. being contracted to produce content for a platform, where I think it stands to reason that you're expected to produce what the platform want.