This is not a reversal. He has been attacking the mail-in stuff the democrats are trying, sending unsolicited ballots to registered voters.
He has ALWAYS said that current absentee balloting, with safeguards, is acceptable.
This is normally what they accuse Trump of, doing things that discourage people from stuff; here he is working to make sure people understand what he is objecting to, and the media falsely claims he is changing his mind.
I agree. Trump has not done a reversal. This crap reporting is annoying.