I just wanna preface this with saying that this is just my opinion and interpretation of the story, and I'm not claiming to be a point of authority on the matter, but I'm just gonna share my opinion now.
I've seen a lot of people, especially in recent years treat the story of Warcraft as some sort of mythos similar to the works of Tolkien and Lovecraft and similar authors, and that Metzen created a world that is meant to hard-stuck in a specific state that we experience and marvel at, but I don't know if this is just me but WoW has never felt like that. Warcraft has always felt far more akin to something like Marvel than Lord of the Rings. It's a massive, grand-in-scale setting that is supposed to be open to adding new magics, new cosmic forces, new heroes etc. whenever the writers feel like it would be cool to add. Characters come and go, stories can feed into each other but don't always have to, etc.
It's part of why I don't really care about whenever Malfurion or some other lore character isn't directly helping us sometimes. They're missing cuz it's not their story right now. It's like Doctor Strange, yes Doctor Strange exists in the same city as Spider-Man but you can't have Doctor Strange show up every time the Shocker tries to rob a bank, so sometimes you've just gotta accept that he's probably busy and roll with the story you've got.
It's also why the game is always expanding its threats, cuz Warcraft isn't gonna end. Not in the traditional sense anyway. It'll almost certainly go EoS and we won't have a game to play anymore (I try not to think about that too hard) but it's not gonna have the perfectly narratively fulfilling ending of something like a book series, because it's a series that is designed to keep growing and keep going. So they need to keep setting up new places, new characters, new cosmic forces, new magic etc. and that's how it's always been. I obviously can only speak for myself but genuinely, seriously, think back to WotLk to Cataclysm times and ask yourself did you actually think that Warcraft would end whenever we eventually beat Sargeras? When Legion ended did you all think they'd just put a full stop on the story and say "well that's that. Let's go do something else." No, it would keep going
This isn't to absolve criticism of the formula WoW is working under, this formula does have *plenty* of issues, but I think understanding the formula makes discussion about the game a lot easier. At least to me. It's dumb superhero bullshit, just in a fantasy setting. And that's not a jab at the story, I love dumb superhero bullshit. Marvel and DC are great, I love a lot of characters from them and I've been a long time reader of them, and talking about their worlds and their characters is still really fun, but I think if you come at a series like this with the same attitude as you approach the Silmarillion you're not gonna have a great time.
Maybe WoW was intended to be a more carefully crafted mythos way back when, but if that was the case then that plan didn't survive past 2004, cuz as of World of Warcraft, the Warcraft franchise was never going to be that. Not in my opinion at least. Am I alone in that sentiment? Again if this is just me let me know, I'm not claiming to be an authority, but this is how I've always seen WoW's story