And before you even mention auto deletion, you can disable that. I think that should be opt in not opt out but, yeah, spam in not being censored.
Censorship is making information functionality unavailable or altering it. Delete it or deliberately make it very hard to access or change it’s contents.
If you click a button or even add a message ( apart from the content ) that is not censorship. That’s why for example I don’t consider it censorship when youtube added covid messages to certain videos.
But since you do want to stick to the spam filter in your email box analogy I would like to propose a solution.
Would you prefer users be able to manage block lists, filters, and such themselves instead of content being removed for all users?
Do you really prefer this large social media oligopoly to have have final say in what the masses should see? Why not let the users manage what they see?
Do you feel the same way about all subjects? Do you support the right of ISPs blocking porn for example?