They could have called it Creative Engine 129030129784.32985 for all that it matters. It's just a name for an engine update, as they do for every new game. They didn't re-write it from scratch; that would be a billion-dollar venture.

From what I've read it's the exact same engine as FO4 with better lighting (and of course, as with every new game, some improvements locally relevant to the gameplay).
But, fundamentally, underneath the fancy lights, still the same engine. That explains the 2008-esque animations, the bugs, the performance issues, and general flatness of the game. It can't be more than "Skyrim in Space" because that's what it technically is.

Because putting a 2 after the name makes a new engine. It's just a new iteration of the same old engine that runs Fallout 3, skyrim, and Fallout 4.

Ill see if I can find it when I'm at my PC, but in an interview a dev said it was still using significant amounts of code from their Gamebryo engine from 97