If you're getting into Elite because you want a better NMS, you will be solely disappointed the first time you "dock" at a space station or land on the surface of a planet (one you can actually land on that is).
Elite has an in depth space combat (and also a ground combat but not as in depth and not on foot) system + their entire galaxy for free exploration in your ship and on atmosphereless planets.
No Man's Sky has the landing on planets and walking around stuff but all of the gameplay stuff is severely lacking.
So basically, both games right now are on opposite ends of the spectrum.
Elite is adding the things that No Man's Sky has right now.
We can believe that No Man's Sky might add the things Elite has right now.