Some 4chan users created a backup bot that auto saves every few hours, so if reddit didn't do it already, 4chan has been doing it for a while. The bot was originally made for 4chan but repurposed for other websites, reddit included.

Yeah, it's all too late. Shit, PRISM was 2007, so there's a copy of everything somewhere. Obviously different ends.

Depends. If they were smart they backed up every content that had a certain number of upvotes and/or a certain number of paragraphs and/or responses. Just to weed out all the 2-3 word comments that no one interacted with. If OP wrote mostly those then Reddit gives a shit about them deleting those.