They haven't come out and said anything straight up but based off what has been said, it seems you are right.
One thing to keep in mind, Nick is young. He realized he made the mistake when he did that follow up video saying he's sticking with Matt. Problem is, Matt didn't seem to feel the same way and for good reason. If someone gave me an ultimatum regardless of what it is, they are the one getting cut. You can't be telling grown men to choose between "me or him" essentially.
The reason I think Nick realizes the fuck up is because he is now on Hosstile's roster with Brett. From what I can tell, Nick wanted Matt to drop Brett. Insecurity really came out to play there but hopefully it shapes Nick into a better person. He is the most popular bodybuilder at the moment and regardless of whether people love or hate him, they are definitely paying attention to him.