I'm worrying quite a bit about many types of content that were supposed to be the focus for the deep dive panel.
Mainly classes as the work done in bfa was not impressive, and they teased before blizzcon that they wanted to put the focus on classes instead of spec.
Therefore we were to expect more information than just X spell and Y spell are making a comeback without any real explanation as to why when they spent so much time at wod explaining why the spell doesn't belong in the game.
For example, healing stream totem; they argued that it's cool to have totems but pressing a button every 30s for a passive heal that is barely noticeable is not good modern design. Why the hell are you bringing that back then???! Same goes for Hunter's mark and many other spells...
For Bfa we used azerite armors, which brought a different type of gear. It will without a doubt go away in shadowlands, but... what do we get instead? are we back to tier set ? (apparently not) will we get stuff with random procs or class effects? Nope, no information again.
Professions will be updated as the what's next panel tells us, but without any core phylosophy exposed... so we continue on the materials management interface, gather-craft simulator, no new mini game associated to it or no rework?
There were so little information about MM+ dungeon, the fact that HM dungeon serves almost no purpose in the game has not been touched...
For people expecting a pvp update, I feel for you, as nothing more than warmode stays has been said. So no plan to expand on the pvp islands? no new arenas? no new pvp systems to get excited about?
The expansion reveal was great until the deep dive. This is utter disappointment... I really wish for them to release an in depth presentation video soon vecause for the moment it seems like the game might not be ready for 2020. And if it is true then we might have another WoD situation where the environments look good but they give up on the expansion 6months in.