The AP is the gold standard when it comes to presidential elections. They have been doing them for over a 100 years.
They predicted that Trump won at 2:22 AM Wednesday morning in 2016 when it was a major surprise for him to win.
Trump had no problem declaring victory immediately.
He is just a sore loser. Especially, since he knows the personal and financial ramifications that this will have for him.
In short, he is not going to retire into the sunset like all ex-presidents.