That's why it's so insane. According to Hitei, it matches the size of the zodiac bull mount.
But then there's the other two words... Nightborne and Space.
I know that we were bound to see some Nightborne stuff due to the marriage of Lor'themar and Thalryssa, but I genuinely cannot wrap my head around what the hell this could possibly be and where it fits in. I love it so much.
If Xal has a fight scene with Lorethemar I would hope it also features Thalyssria. As high Arcanist they haven't established how she fights but with that mount I'm imagining her summoning constellation animals. Nightborne Constellation Bull mount? (Possibly making way for an Astromancer class or Nightborne Druid forms?)

At the very least, it means the Nightborne are likely gonna be relevant in Midnight, which is nice. As for the space bull? Eh, they got astrologers.
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IF Midnight brings us to space, we're likely seeing Azeroth's celestial bodies. Outside of that? Light and Void realms might leak into Azeroth. Heck, The Void's already leaking VIA the Voidstorm.

I think we should avoid further blurring the lines of things so that everything is the same/boring and let that be a night elf thing and let nightborne be their own thing. I don't care for the justification here just my two cents with every race/faction/character being melted into unmeaningful, indistinguishable lore blobs of samesy goals and values.
Sargeras is going to be the last titan and the rest of the Pantheon will die.
12.0.5/12.0.7 - Isle of Fangs
12.1 - Lordaeron and Undercity.
I think I'd prefer it not necessarily be a druid hint, but more lore building on the Nightborne if we're going the constellation way. The Nightborne Star Augars are a really cool flavor that could maybe be expanded upon.
Part of my is thinking it's a construct of some sort which could also be cool.
Although I've always sort of felt the manasabers were a pretty lame mount. They're cool, but they are kind of boring. Giving Nightborne bulls would be a really interesting move. Not sure which way they'd go about it, but it'd be fun.
Tomorrow will be an agonizingly long day...

We gonna go to the moon.
Maybe the Moon Kinght joke I made hit the mark...
Come to think of it, it would make sense. Say what you will about the patch cycle, but Endwalker base game is pretty much scene as a perfect finale for a story arc that has been going since the game began.
Where did we go pretty much halfway into the story: The Moon.
What is the middle part of the Worldsoul Saga: Midnight
That would mean TLL should be about going to a facility created by the ancient precursors, to uncover secrets that....hey holdup!

Come to think of it, Star Augur Etraeus was the first time we learned about the Void beyond Azeroth's Old Gods, wasn't he? (In-game at least, I'm pretty sure Chronicles also revealed that.)
I suppose more Astromancy could fit well with Midnight then, if it's focused on stopping the Void.
Stars are an interesting part of the lore. They are an intersection of Void, Light and Order really. Perhaps representing the genesis, preservation and destruction of their life cycle.
The Silent Star was 100% of a Void entity. Its maybe possible constellars weren't always associated with the titans but something try manipulated into their designs

Constellars are 100% Order-based.
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I imagine they're not all associated with the Titans, but if Rygelon is anything to go by, they're 100% Order-based.
Order likely assigned certain constellars to check-up on the Cosmic Hearts of each Zereth in-case something ever occurred there.
The Jailer literally had a Constellar join him consensually. It's the wild west, baby.