Lover's Lab is a microcosm of why Bethesda doesn't need to change. The Creation Engine is a 'new engine'. I mean, before Skyrim the engine used C++ based code, NOW it uses Papyrus...that's NEW. Animations are handled outside of the game engine and the file format is different. That's new too! See?! New-new-new!
People talk about how the enemy AI in FO4 is improved. NO, that's the devs making Combat Style packages that use cover, dodging, etc. more than they did in Skyrim. It's the same shit with different percentages. The same thing can be done in Skyrim with the Creation Kit and new Combat Styles.