A new class and/or race? … While they already can’t balance and can’t keep relevant the existing examples, it’s more likely than not. These ideas sell expansions - marketing will hand down edicts of “thou shalt” and it will happen.
So yeah, check there.
Biweekly balance patches? While I think they should, I know they won’t.
Mission table? … Eh, this is one of the more/most benign of their systems, and one of the few they’ve actually kept alive in some recognizable incarnation over the years. This I would say keep iterating on.
Don’t particularly care about the companion app.
The “Path of the Titans” systems, though… yeah, the carnival goldfish gimmicks needs to be axed. Stop developing with styrofoam and papier-mâché and have an expansion that’s an actual expansion, not just another prolonged “season”. I want an addition to WoW, not a cellophane pop-up tent thrown up in the back yard.
As to the new dungeons… yeah. WoW was at its best and strongest before these distraction and throw-away systems. Wrath? Burning Crusade? WoW’s yet to reach such heights, and all these pithy throw-away efforts are a big part of why.
Stablize the core balance of the game, get back down to basics, and with that foundation solid and crystallized, go nuts. They should bring back the Onyxias and Obsidian Sanctum type raids. They should throw instances at us like Auchindoun - with different wings with diverse themes and threats. And they should load us down with rewards to shoot for within them - cosmetics. Burning Crusade instances are still relevant because they contain totally unique appearances - even if all they are is a color-variation on other armor, there will always be those who will seek those out.
You want your work to have meaning and impact for all the game’s lifespan, your investment of time and effort to continue to draw people in years later? That’s how you do it.
If only they stop trying to slop in all these passing fad gimmicks and throw-away systems, we could see WoW have a renaissance.
The fundamental recipe for WoW worked and can work again.