Make sure they stayed deleted. A youtuber tried this multiple times and every time his posts would be restored after a few minutes, and reddit refused to comply with data protection laws and delete the data on request.
As far as I understand, data protection laws do not require the vendor (in this case Reddit) to delete all your data. They are required to delete identifiable information, disassociating your posts/comments from your username seems to be enough to satisfy the GDPR.
I did make sure that my content has not been restored. After using PowerDeleteSuite to edit and delete all my posts, I was still able to find comments of mine on reddit using Google search, despite my Reddit Profile showing "this user doesn't have any posts."
Apparently, that is an issue with older accounts with over 1000 comments, you can only acccesss the latest 1000 posts/comments using your profile.
I then sent a GDPR request to get all my data (all my comments, and the links to them), then used a tool called" shreddit" to edit all the posts in the GDPR request csv file.
I did re-check a handful of posts a few days later, and they all remain edited.
I have sent another GDPR request 30 days later, and I will get another csv list of all my comments and I will be able to see if all of them remain edited. Once that is verified, I will delete my Reddit account.