Written by GW eh? - Like age of Sigmar! xD 

Don't even get me started on 40k Age of Smurfs......

Looks to his left at the now extinct tomb king army "weeps" WHYHYYY

Hmm. Grey Knight in game or Deathwatch (design several chapter). Yes, I want that in the game as a playable character.

Still, I would like to see the Grey Knights in action in some way shape, or form.

Storm Wardens showed up in the Deathwatch Mobile game. The Watch Commander was one of them.

Best line about them-

'They keep secrets so well that they make the Dark Angels seem friendly and open!'

I bet the Stormwatchers will be better explained as we purge our way through Caligari. I hope so anyway. 

Excerpt from Games Workshop and Fantasy Flight Games, Deathwatch Core Rulebook.

ISBN: 978-1-58994-778-8 Product Code: DW01 Print ID: 781JUN10

 The history of the Imperium since the Horus Heresy is not

a continuous story. There have been periods of rebellion

and anarchy, times when the balance of power has suddenly

changed and history has quite literally been rewritten. Many

of the subsequent foundings of Space Marine Chapters

belong to these troubled times, making it almost impossible

to ascertain when some Chapters have been created. It is

believed that of the one thousand or more Chapters thought

to be in existence today, more than half are descended from

the Ultramarines, either directly or through one of the

Primogenitor Chapters of the Second Founding.

It is not known how many new Chapters were created by

the Second Founding. Many records were lost during the Age

of Apostasy, a troubled time that bestrides the history of the

Imperium like an impenetrable veil. In all likelihood, some of

the Chapters created during the Second Founding have since

been destroyed, leaving no records of the deeds. Others have
been lost in more recent times, and their names are now all that
remains of them.

https://warhammer40k.fandom.com/wiki/Stormwatchers

40k figuratively leaves a HUGE door open for any player that wants to create his own chapter and add to the lore. There are tons of player created chapters that exist and aren’t listed anywhere. Almost anything can be canon in 40k - as long as you aren’t affecting a major storyline. (Hell, I’ve created my own chapter with backstory) 

sorry, I realize this is a necropost 

Chapters are founded all the time to deal with specific threats or guard specific areas. The Astartes Praeses Chapters were all founded specifically to guard the Eye of Terror, for example. It's perfectly acceptable to think there's one in the Caligari Sector too, and since it's a new Chapter, the writers can get away with saying they work with the Inquisition a lot since it's a troubled sector.

I'm sure we'll learn more about them as the story progresses. Maybe they'll get mentioned in a GW publication at some point. I think the Storm Wardens from the FFG RPGs managed to get a mention once too.

You can't do interesting new stuff with old chapters. Going by the over the top bloodlust of the marine from the Martyr the Stormwatchers might very well be compromised. And that's not something that flies when you call them the Deathwatch or the Grey Knights instead of a new chapter.

It's the reason why Relic went with the Blood Ravens for their huge story focused games instead of the Ultramarines (who only appeared in the generic 40k stories like Space Marine and Winter Assault).

Provided of course that Thorn is telling the truth about who he works for.

*shifty eyes*

Then again, a new chapter would be cool.

As for the Stormwatchers, it really does depend on how well its done. And who knows, if the game does well, we might see some of the others in the future.