Let me wildly speculate...

So, after saying he is changing his convention speech "to bring the whole country, even the whole world, together" (ha!), he has turned up there looking "emotional" (I actually agree with that):

Wouldn't it be funny if the near death experience has genuinely made him religious, and in the worst possible way - such as believing the Messianic guff that his Christofascist base has always believed, and that he was saved by God to win the election.

Or (and I know this is wildly unlikely) he sounds humble for the first time in his life and thanks Biden for his kindness and says his rhetoric about the Democrats is going to change.  (I mean, this is so unlikely I find the previous speculation more plausible.)

What in fact will happen, I would bet money on, is that he makes an awful speech which amounts to "we have to unify America again, and that can only happen if everyone agrees with me".