I don't have a solution to your question, but I started deleting my account annually so that it was harder to track me, spy on me, and sell my information.
Before I started doing that, I had an account with 900,000 karma. When you asked for your account to be deleted, the Reddit automated response was 'Are you sure you want to do this? After one month, all of your content will be deleted.' And that's what happened. If I look on reddit, my posts were gone. On google, I could find people mentioning my username but not any actual posts by that account.
TLDR: They used to threaten you with deleting all of your posts, and, based on my experience, they did exactly that with my old account.
It's kinda funny to see them flip to threatening to keep your content.