Sure, but those other beings didn't have a deal with the guy who runs death for the entire universe, and those other planets didn't have a Helm directly connected to (and made in) the Shadowlands. They already stated (on the official website/Blizzcon "What's Next?" panel) that Sylvanas' intention for the burning of Teldrassil was to, in a way, "overpopulate" the Maw with souls. The whole Blood War was part of this. That wasn't exactly speculation, and could be much more directly tied to the "broken machine" mentioned.
https://worldofwarcraft.com/en-us/news/23187291The machine of death is broken, and players entering the Shadowlands will find the realm of the dead in disarray. In the natural order of things, souls are sorted and sent on to an afterlife realm appropriate to the lives they lived, but now, but over the past few years, all souls who have perished—including the innocents slain at Teldrassil—are being funneled directly into the Maw. The Shadowlands are starving for anima even as the Maw continues to grow from the glut of fresh souls.
Sylvanas has been seemingly perpetrating acts to bring about great amounts of death and destruction. In partnership with the Jailer, they have been working toward a common end for some time.
That could simply be connected to quite a few other things to "break" the machine, like all the other things I mentioned and mentioned by the OP.