Sure. But the idea of what's "good" is extremely subjective, especially in games with a devoted fandom. I found the Lorewalkers a great idea in MoP, and I'd like to see that type of reputation again to expand the lore in a new, unexplored area. Other people might have found it tedious or a waste of time. I thought the Allied Races were fun, but could have been a bit more fun/unique - plenty of people did not, with plenty of MMO-C posters alone demanding that Blizzard "delete Vulpera" and such. I don't mind pathfinder to get flying, while other people either don't want flying at all, or they want to simply be able to buy flying like the old days. I generally liked how most classes played in Legion and BfA, but other people prefer how classes were in older expansions.
Every expansion has had pros and cons. Every bad expansion has had a couple things that people generally liked, and every good expansion has had flaws. The balance comes with listening to players in many regards. The expansions that have been remembered well followed that rule - mass complaints about issues were addressed and changed to be more fun or fair to players. On the other side, there have been expansions that have had flaws from the get-go that were never changed or expanded on, so it remained a problem for players the entire time (like issues with garrisons, Warfronts, island expedition loot, Legion legendaries, Heart of Azeroth/essences, etc).
So, yeah, Blizzard could write a compelling, new story in an expansion that's fun to play. They have 15+ years of experience and feedback to fall back on. However, there have been many times that they've simply stuck to their guns about things that are mostly failures. It's possible BfA could, ironically, open their eyes and see what went wrong. Or, it could entrench them further into systems and stories that haven't worked, out of sheer stubbornness.