Blizzard
Thanks for raising the concern! Itemization is definitely a big piece of how this will all need to fit together in order to work, and the goal would be for each season’s dungeon pool to provide deep and varied loot options. In some cases, that may mean modifying or supplementing loot from older expansions’ dungeons. If we were to mix in M+ versions of Mists of Pandaria dungeons alongside new Dragonflight dungeons, for example, we’d make sure that the resulting seasonal pool provides full itemization coverage for all specs. It’s likely that we’d also take a close look at trinkets in particular from Mists dungeons, which weren’t necessarily created or tuned with cutting-edge performance in mind (since back then dungeon difficulty capped out at Heroic; Challenge Mode only gave cosmetic rewards).
If we ended up landing in a situation where a specific item from the prior season’s dungeons was beating higher item level alternatives from the following season, we’d make tuning adjustments to correct that. You shouldn’t need to worry about “missable BiS” being a thing. But on the other hand, we’ve heard tons of feedback about how re-farming Soulletting Ruby, IQD, etc., every season hasn’t exactly felt like a compelling progression experience, so we’re excited at the chance to shake things up there.
Aside from a complete itemization refresh from season to season, our hope is for the dungeon gameplay itself to feel fresher, and like a new set of puzzles for the community to solve each season. We’ve seen really mixed (often negative) experiences in the past when we add brand new dungeons into an existing pool of dungeons that the community has already mastered, and try to set them up as equivalent in terms of difficulty and rewards. And while the hardcore M+ community may not experience this issue firsthand, it’s hard to overstate how daunting it can be for someone to try to get into M+ PUGs or try a new role like tanking for the first time deep in an expansion, when the established community is largely focused on routing micro-optimizations and time-saving tech, and groups likely assume complete baseline knowledge of all boss mechanics, positioning, target priority, and so forth.
We’re well aware of the risk that it might be disappointing to not get to experience M+ versions of all eight new Dragonflight dungeons during the first season, but our hope is that mixing in some dungeons that have never before had an M+ component (e.g. Shado-Pan Monastery) will make for a fun new experience there, and that in the long run the complete rotation will make for a much healthier and more dynamic Mythic+ experience over the course of the expansion as a whole.