Quote - We already have the facility to add advisories to our posts ('language', 'nudity' etc.).

Why not two more: 'Off topic' and 'Warning'?

The 'off topic' advisory would normally be applied by the poster. It would allow for diverse discussion to happen within a thread, and yet make it easy for people to view the whole thread without those posts by modifying their forum profile to ignore off topic posts.

The 'Warning' advisory would normally only be applied by a moderator. It would serve as a public warning that the post was inappropriate in some way. Users can choose to not see posts flagged with a 'warning' advisory by modifying their forum profile.

This approach makes use of the forum functionality (advisories) that already exist and results in no deletions or censorship at all. It is left to each user to decide what they want to see.

I think this is an excellent suggestion.  It allows those who are interested in the thread, yet ignoring it over unpleasantries, to participate.

It would be nice if we could make this work.