Since I seem to have missed the mark with the OPs point, he's mostly referring to end game leveling zones in the future.
I feel like Pandaria was cool, because the threat was shared (sha) between the zones, and you had both alliance and horde stuff and the local stuff.
While in Legion each zone was pretty cool individually regarding the quests, in my opinion it was way to disconnected, which is the result of the ability to choose your leveling path. On the other hand WoD had a very nicely done story, and everything was connected into the garrison campaign against the orcs, but it was too streamlined for my taste. I always preferred the ability to choose, while still being connected to the main story (Northrend/Outland is a good example, although the quests themselves are not stellar).
So my hope is that they will make enough zones to be able to choose multiple paths (unlike Legion where you had to complete all zones, but you could choose the order).
P.S. a problem I had with legion questing is that, after the massive invasion at the Broken Shore, and all over Azeroth, we go close to the main invasion point, and find the zones almost intact(with the exception of Azsuna start), with demonic presence just barely beginning to show in very small amounts. While the stories were very well done, it didn't feel that urgent and dangerous, not enough for the biggest legion invasion yet. So I hope that they do the future zones more according to the main story they are trying to tell .