First, I'm a little disappointed at the claims of the dev in the video that they are the first to do this kind of thing, I mean, I just imagine DB in the back politely raising his hand and coughing...
That aside, I like NMS, I like the art style, it isn't like Elite but it is interesting. I can appreciate Rembrandt and Van Gogh despite their artistically divergent styles (one more true to life and one more interpretive). I think what their team has done is exciting and is good for procedural generation tech and space games. I only wish Elite could have gotten this kind of publicity.
A couple of things I took away from the video. Elite is extremely impressive because not only does it attempt to take on the same challenge of NMS (procedurally generating everything), it attempts to do so with graphical output similar to AAA teams with 800 people, the majority of whom just make the games pretty. While I appreciate both art styles, the one is certainly more taxing and difficult to produce than the other.
Second, I agree with his statement about procedural generation becoming supplemental to the game industry (or something to that effect). After playing Elite it's hard to find other games big enough for me, they all just feel so small. I think as PG gets smarter and has more teams incorporating and refining it we'll really see it take off. What started in 1984 with Elite will likely end up changing the way the entire industry builds worlds, levels, enemies, creatures and everything else.
I'll add my voice to the other posters that have explained seamless vs not. Transitions across systems are seamless, transitions between instances are not. So when you change instances (supercruise to normal space, normal space to supercruise and hyperspace) you end up with what is for most players a very brief, very well masked pause. For me it is sometimes instantaneous (you also have to understand that each system on the gal map has to be generated as its own instance so you cannot get a seamless generation from one to the other necessitating hyperspace and I would guess NMS will use a similar mechanism for systems to system travel). If you drop out at a nav beacon and lock a target you can fly all the way to it without ever having any transition, but you have to stay in normal space. That's probably not feasible because you'd take a very long time to get there at a meager 200-300m/s but you can drop out 100km from a station and fly to it in a few minutes, approaching the station will be 100% seamless.
In the end space is big and FDev decided not to compress the distance to make the game "like a scifi book cover" so instance changes became a necessity, but I think we'll see it continue to be optimized and improved, it is really close to seamless as it is.