If he kicks them out, the only people to be up in arms wll be the CNN people and those who hang on their every lying word.
Millions of US see CNN and the other denizens of the MEDIA only when forced to see them while in line at a coffee shop, airport concourse, or walking by a display of TV sets in a big box store.
There are many other sources of the truth, and you are looking at a prine example NOW.
The news cycle will be “Trump bans reporters - what is he hiding?” and people will think he is hiding something. Let them stay, he trolls them perfectly anyway and it give him an opportunity to make the news about him proving them wrong which he keeps doing. Anything seen as blocking a ‘free press’ will just feed the “Trump is a dictator” meme.
Sometimes you want your enemies close.