"just" is doing a lot of work there. Everything is "just" an evolution of something else. Doesn't mean it's not novel or clever.

The wing folding mechanism is pretty novel as far as I'm aware. The idea of quad hover to forward flight isn't new or unique but the specific configuration is something I haven't seen before. NASA was working on some that tilted the whole wing not this folding design which uses fewer motors compare to the old NASA Greased Lightning test article.

https://www.youtube.com/watch?v=kXql26sF5uc

Osprey has a common power shaft between the engines for fault tolerance, constraining the structure's design, such as the lack of dihedral. This has a different set of design constraints and a different solution to propulsion failure.

The hinge mechanism and the control dynamics.