They're lying about copyright law to scare people into paying them anytime someone makes a video of someone's reaction to anything. They're also abusing YouTube's copyright system to take down videos they deem infringing by filing false DMCA notices (if a YouTube accounts gets three strikes, it is deleted. They literally can wipe out their competition). They're trying to convince people that if they make a reaction video, they must give all rights to them so they can monetize it and "compensate" the original posters in some way, taking a cut.

Problems:

1. You can't copyright a format. Just like no one can hold the rights to all "detective stories", no one can hold all the rights to "people react to something".
2. You can't "copyright" a name (that's a Trademark, different set of rules)
3. You can't trademark common descriptive phrases (like the word "reacts") - Sony recently tried to do this with "Let's Play" and suffered embarrassing press (plus the wrath of the internet) and a double-rejection from the US Patent and Trademark office.
4. Even if they had some legal standing, prior art (videos and even TV shows that came before) have already used this format extensively, in some cases for decades. They are not the inventors.
5. False DMCA notices are purjury. However, those affected must pursue the matter in court, which few can afford to do.

basically these guys are moronic sociopaths with a terrible legal team to even THINK this has a remote possibility of working, but they're already doing real damage and YouTube (who's reputation is quickly tanking due to other high-profile turmoil with content creators) so far hasn't done much to stop the damage they are causing. They are also censoring criticism of their plans anywhere they have the power to do so.

TL;DR fucking scam artists abusing the law.