Has SE not learned anything from 2.0/3.0 release's?

[Rhysati]

Legion only worked because they changed how the entire game worked in open world content. Everyone is always being phased into different instances of the same zones, so you can barely ever see anyone.

That's completely and totally untrue. The game is one giant mega-server with sharding. But there are mods that quickly find you a party for anything you are doing and move you to the correct shard seemlessly(no loading) to put you with full raids of people taking down world objectives. The worlds are heavily populated and you see people all over, but they tried to keep each shard limited to a certain number of players to reduce server stress. It's the model that a lot of games have moved towards and it works great.

[Gwendi]

-snip-

We must have had very different experiences with the weeks leading up to and immediately following Legion. I remember people disappearing and reappearing at random, being shafted into empty copies of Stormwind, and an entire protest movement from the roleplaying community that went all of nowhere because Blizzard was too focused on how great their sharding was that they ignored the damage it did to the RP community.

It's true that it reduced server stress a lot (and holy crap there was a ton of stress before they patched sharding into the main cities), but it wasn't a perfect solution.
(Also when players have to make addons to fix the game for the devs, that's not a good thing.)