Yeah. This was pretty upsetting to discover. I had been blindly using my reddit upvote history as a supplementary personal log of sorts, for many years. And most of that's now just gone.
Thank god I haven't made over 1000 comments or posts with any one account.
The data's all still in the database, but due to their caching setup, only the last 1000 of anything is publicly indexed. While everything's technically reachable, it's all deep web. To recover something private like upvoted or saved posts, we're talking heat-death-of-the-universe, through a full-table-scan squeezed through brute-forcing a search box, while authenticated, with rate limits.