WoW for the most part wasn't too cosmic with its lore for a long time. The most there was is that the Titans are powerful beings that go around ordering and putting life on planets, including yours, Azeroth, and one of them went insane and decided to destroy everything. He rounded up some demons to help him and is eternally mad that his attempt to destroy Azeroth failed. Otherwise, you also have that an evil wizard opened a portal to another planet and let the orcs in. That's it for big cosmic stuff and pretty much sets up most everything in Warcraft to happen on Azeroth, give or take some religions that various people have that are more or less acknowledged to be true, but even then they're pretty confined to those people.
Over time as WoW declines to where it is now, the lore team (who isn't the original people for the most part) feels the need to go more cosmic and set up this huge system of opposing cosmic forces. For example, the Light, which was always good and the humans worshipped it as Totally Not Christianity complete with cathedral and bishops and priests, became some huge cosmic force that could be bad? Or maybe good? Or neutral? Who wants this shit? Who asked for it? Who enjoys this sort of thing? Pyro, of course, who loves this stuff and wants to churn out a bunch of theories about what these cosmic forces mean and where the lore is going. He didn't even like the era of WoW lore people enjoyed, he liked the parts everyone hated.
If you want to know who he was when he was doing WoW, there's a moment when he gets to Ardbert first explaining that light is flooding the First, and Pyro talks about how this is what he always wanted in WoW. Nobody wanted this in WoW. Everyone liked when the Light was a good thing that human paladins wielded as both weapon and shield because they were pious and righteous. Only someone who loves lore books and reading wikis more than enjoying a story likes this idea. So Pyro was the autistic guy you saw in your Youtube recommendations making videos about how WoW totally needs to show you how bad the Light can be, because a lore book they'll retcon in a year or two says it's a big cosmic force that can be good or evil. And then one day he shows up in your Youtube recs playing FFXIV and having a meltdown over how Blizz betrayed him and the rest is history.
Now give me every puzzle piece you have because I feel like a massive faggot for typing all this.