I did edit the posts. First edited then deleted immediately, the last two tries edited in batches, then deleted weeks later. No dice. I'm sure Reddit has far more than one backup and it's clearly easy enough to automatically detect and revert mass edits, even done gradually over time.

Another route is to sue them.

That's going to be pretty difficult and unlikely to succeed. They're worse than the music industry. Here's the applicable blurb from their TOS:

You retain any ownership rights you have in Your Content, but you grant Reddit the following license to use that Content:

When Your Content is created with or submitted to the Services, you grant us a worldwide, royalty-free, perpetual, irrevocable, non-exclusive, transferable, and sublicensable license to use, copy, modify, adapt, prepare derivative works of, distribute, store, perform, and display Your Content and any name, username, voice, or likeness provided in connection with Your Content in all media formats and channels now known or later developed anywhere in the world. This license includes the right for us to make Your Content available for syndication, broadcast, distribution, or publication by other companies, organizations, or individuals who partner with Reddit. For example, this license includes the right to use Your Content to train AI and machine learning models, as further described in our Public Content Policy. You also agree that we may remove metadata associated with Your Content, and you irrevocably waive any claims and assertions of moral rights or attribution with respect to Your Content.