you still can...
Reddit isn’t selling access to the public comments; it’s selling database access to all comments, previous edits, deleted ones, currently public ones etc.
Still it would've been more effective
They have the edit history. All you're really doing is posting a big old flagpole on your comments that says "this account was previously run by a real human being" because bots wouldn't have a reason to edit comments in protest. No matter what you protest-edit to you're only making their job easier. The most effective way to "stick it" to reddit these days is to not interact with it whatsoever.
There is nothing stopping you.
Infact there are tools that will mass edit your comments.
If you think that anyone who cares hasn’t already scraped the content you’ll be wiping for the purposes of training one ML model or another, you’re kidding yourself.
Because they'll probably just ban you for spam then revert all changes via backups I assume they most certainly have.
That, or probably end up IP banning you for editing 2 comments because fuck you.