Reddit can restore your deleted posts. However, if people flood them with GDPR / CCPA delete requests, they may become liable for lawsuits if they don’t comply.
It sounds like their current policy is to not delete your posts even when deleting your account, but there may be grounds for legal action here.
I believe it’s less straightforward than that. Under GDPR, consent can be withdrawn, you can’t give an irrevokable consent.
See https://kbin.social/m/RedditMigration/t/34112/Updated-Reddit-is-quietly-restoring-deleted-AND-overwritten-posts-and#entry-comment-161522 and https://kbin.social/m/RedditMigration/t/34112/Updated-Reddit-is-quietly-restoring-deleted-AND-overwritten-posts-and#entry-comment-149886