As someone brought up earlier, I think BotW demonstrated how you can make the world a living place without it being 100% destructible. How that would translate to a MMO, I don't know. However, there were several moments when I had that EQ vibe when roaming around, looking for the next thing to do. If someone would have been LFG for Shrines, a Hinox, or seed runs, it would have been a lot like EQ. I may be completely off on this but I believe if you look at EQ, look at BotW, and borrow from each, you have a pretty solid game.
I still believe you could essentially remake EQ. If you were to bring the best pieces of each expansion through PoP with the end game being the PoP storyline, it deserves that chance. Runescape did a complete overhaul of their game. I never liked their game but it's pretty amazing to make they put that kind of effort into their game. I'm not sure it attracted new people but I thought it was exactly what EQ should do instead of making expansions.