If this was Twitter growing a spine it would say he was suspended, not that he deleted his own account.
My bets are on that either he was hacked somehow or that he did it by accident. But it's possible someone convinced him that enough was enough re: his twitter shitposting habits?
The President's personal account is showing up for me, I see 41.7 Million followers, just no tweets. Either DDOS, or he deleted it, or Twitter is doming something, one of the 3.