Gonna close this off cause I've done all that I can. Thanks to those who sent through PMs and posted here.
@NuttsnBoltsStill a post on my thread by him. The nuke must have glitched.
<Snipped quote by NarayanK>
As well as permissions to delete posts in their own threads.
It's kind of obvious he's not here to roleplay.
Hmm, it would appear that the post autosave system might actually override a more general textfield autosave preference when you go over the six hour limit, and proceed to nuke the content, which is a bit unfortunate.