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.
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.
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.