Thanks to everyone who suggested editing the comments before deleting them, but I decided to just go through the last 3 years of comments and edit them instead (yay, macros).
I could only go back 3 years on the comments in RES, and I'm pretty sure comments to subs that are currently private weren't shown. I was actually looking for a specific comment to archive, but r/TheOrville is private and none of my posts/comments were visible.
The one toward the bottom with 761 points on the post titled "What's the worst adult tempter tantrum you've ever seen or heard about?" was a really good story, too. Maybe I'll share it here, sometime.

5 Comments
wizzor@sopuli.xyz · 2 pts · 3y
I have been considering filing a GDPR right-to-be-forgotten request. They cannot refuse it, must actually delete the data and do so under penalty.
MentallyExhausted@reddthat.com · 1 pts · 3y
These fuckers are restoring overwritten and deleted comments.
Taleya@aussie.zone · 1 pts · 3y
They're going to have a very very bad time of that under GDPR
aka_oscar@beehaw.org · 1 pts · 3y
Every time i do something irreversible there's someone who had a better idea to deal with it. Congrats on your exodus
bowreality@lemmy.ca · 1 pts · 3y
Don’t delete your account yet. Some of mine came back.