Yes this is true, they're a talent management company. A couple months back Night Inc also bought The Roost bringing H3, Phillip DeFranco, Ludwig and others under their umbrella too.
Mr Beast went independent since this was originally posted though.
DeFranco lost me when he went too political. As do most entertainers. There is something when they go political, they lose what got the audience interested in the first place. Same with Rogan. The appeal is a bunch of random funny news rather than the same boring crap.
I know beast was with a company called night owned by reed duchscher and they company claims to work with a lot of other streamers, so it's at least true-ish.