Just some thoughts about Battle For Azeroth which have been bouncing around in my head over the last little while.
A lot of people seem to think BFA is a "bad" expansion. I confess that I don't really see this. To me, BFA seems more or less like Legion. I liked Legion, and I like BFA.
The base zone stories in BFA are quite good. I do think that effectively requiring you to level both a Horde and an Alliance character will be deemed a mistake in hindsight. But as I have max level characters on both sides, it's not much of a barrier.
As for the faction war story, I didn't have very high expectations, thanks to my predictions about the nature of war. I think BFA has shown that the basic logic of those posts were sound and correct. However, Blizzard has managed to exceed my expectations in the handling of the war. So where many other people seem to be disappointed, I'm actually impressed that they did as good a job as they did.
Azerite armor was a decent attempt at fixing the issues with both artifact weapons and legendaries in Legion. However, Azerite armor really demonstrated that character power must be monotonically increasing, as mathematicians would put it. Players will not accept a temporary reduction of power now in exchange for future power later.
And as always, it falls victim to people theorycrafting the best options, and everyone ignoring all the others.
Island Expeditions, Warfronts
In my opinion, the last two expansions gave us several solid "evergreen" systems. For example, Warlords gave us the modern LFR/Normal/Heroic/Mythic raiding structure, which is quite good. Legion replaced dailies with World Quests and Emissaries. Legion also gave use Mythic Keystones, which are excellent small-group content for players in the higher tiers.
I believe that Blizzard is looking for a new system or mechanic for players below that tier, for whom Mythic Keystones are not a good fit. Players who are casual, and primarily use Group Finder to make groups instead of guilds or Party Finder. Basically the type of player who currently tops out in Heroic Dungeons or LFR.
Blizzard basically took two cracks at the problem with Island Expeditions and Warfronts. I'm not sure either was entirely successful. Though here, it's hard to tell. The vocal part of the WoW player base, the people who post on the forums, are not the target audience, they're in the tier above. Overall, Warfronts have probably been better received than Island Expeditions.
I think Blizzard has been looking for something for this group of players for a long while. Their last attempt was Scenarios in Mists of Pandaria, and given that Scenarios never appeared again, we can gather that they weren't successful.