It’s quite the stretch to call this a game engine, rather than a tech demo for clever locking strategies.
There might be some cool data container ideas or primitives. Those could have useful applications. But it isn’t really a “game engine”. Nor does it seem like an interesting way to build one.
Is it a house?
Does a house need a foundation? Yes. Is the foundation the same as the house? No.
They're building a game engine, but it is not an actual engine yet. Just one core component.
If what you were working on--for the entire time you were working on it--was a completely different thing from a house or from a game engine, how could you clame to have built a house or a game engine? Putatively, what you were working on what an entirely different thing from the result.