Consider instead editing all of your comments so that they link to one of the threads about the blackouts and say that you moved over to Lemmy, with a link to a Lemmy instance and something explaining the Fediverse.
You can use Power Delete Suite to mass edit your comments. I personally used the pkolyvas fork which adds a 5 secs timer to comply with new API rates (but then it's very long so you have to keep it running for a few hours).
For example this is how most of my comments now look like:
(don't copy the same text otherwise you're just helping Reddit justify undoing the edits by considering them spam)
You might want to get on it before they close the API most outside bulk scrubbers operate on. July 1 might be too late.