If you have a good audit log, it really doesn't matter. You can always restore it if need be.

If you have no audit log(or a bad one), like lots of apps, then you have to care a lot.

Personally, I just implement a good audit log and then I just delete with impunity. Worst case scenario, someone(maybe even me) made a mistake and I have to run undo_log_audit() with the id of the audit log entry I want to put back. Nearly zero hassle.

The upside, when something goes wrong, I can tell you who, what and when. I usually have to infer the why, or go ask a human, but it's not usually even difficult to do that.