I think Ocasio has a higher single tweet. But the claim was that his averages are near 15-25K, when he's fairly consistent with hitting 80K+ on his tweets.
I'm not condoning it. Hell, his retweets today are incredibly stupid for a Presidential account. But it's not a correct assessment.
Nov 26 highest was 170k: https://twitter.com/realDonaldTrump/status/1067015026995879937
Nov 25 highest was 127k: https://twitter.com/realDonaldTrump/status/1066685057648214018
Nov 24 was 165K: https://twitter.com/realDonaldTrump/status/1066478927143677952
Nov 22 was 202K: https://twitter.com/realDonaldTrump/status/1065576088779272192
Nov 21 was 195K: https://twitter.com/realDonaldTrump/status/1065225940836458496
Nov 20 was 184K: https://twitter.com/realDonaldTrump/status/1065102519188275201
Nov 19th was 174K: https://twitter.com/realDonaldTrump/status/1064596708875747328