I had heard that the President seems to take to heart the advise of the last person/people who speaks to him.
I don't know how true it is, but remember the day when he said he wasn't big on due process?
The next meeting he has is with the NRA and he changed his mind when he went out that day and spoke about it.
If Hannity came up with the idea the of being the last person to talk to him, that's good strategy on Hannity's part.
Trump wakes up the next morning with Hannity's viewpoints.
While Hannity is not perfect, if it is true that the last person talking to him gets the nod of approval, it's a damned sight better that talking with Chuck Schumer or Nancy Pelosi before he goes to bed.
If it is Trump's idea, then maybe he is trying to get the Fox news/ Conservative prospective of the days events, which is a lot better than talking to someone at CNN.
Just throwin' it out there.