Shouldn't it be up to the artist? What if the artist is ashamed of his/her work?

Not even the artist, if they are ashamed, they get depressed and depressed artist make good art, so it is an absolute win.

If they're ashamed, they'd not publish it..

If they regret it later, it's likely because society is bullying them into pretenting to be _very_sorry_(tm) about expressing their ideas.

If they genuinely change their position, then, in a mature society, they can own up to their past and all will be good.

But that's not the direction we're moving, no, in todays society, people must constantly revise their past, not to fit with their own values, but to attempt not to be cancelled.