I’m pretty sure President Trump is not allowed to announce he’s running for President yet due to certain laws. He didn’t announce he was running for President the first time until June of 2015, almost 1 1/2 years before the election. I don’t expect an announcement from him until Summer 2023.
There's no law that says he can't start his campaign now. Democrat John Delaney officially kicked off his 2020 campaign in July of 2017.
Trump is uniquely positioned against all the other candidates in that he has already served as President of the United States. If he wanted a second term, he should've officially kicked off his re-election campaign the minute Joe Biden was sworn in. That he didn't tells me that he isn't serious about running again. But the teasing allows him to keep the fundraising going.
Trump is right.