We know that the post-ROTJ canon is going to be altered, if not wiped out, and yet we have a lot of Mara Jade and the like in the other FFG games.

As I understand it, all EU is now Legends. That includes both post and pre ROTJ. So things like the Darth Plagueis or even the SWTOR novels are also now legends and no longer canon. But at the same time, they're no longer canon pretty much the same way they were always not really canon. Namely that the movies trumped them.

So Mara or Thrawn are still there, unless a one of the movies actually points out that they aren't. Like lets say that in Eps 7 they state that Luke never got married, and in fact never had time for a relationship at all. That means Mara never existed as Lukes wife. But could in theory still have existed as the Hand of the Emperor... Likewise if the movie takes place 30 years after ROTJ then unless they state it, Thrawn could of happened, just wasn't mentioned in the movie.

The only real difference between what Disney did and the way it was, is now everything will be canon. All movies, books, even games. Although it's possible RPG's or even mini games like X-Wing won't fall under that since they're not telling a story. Even though you tell a story with a RPG it is not a narrative in of itself. But the source books could be, since they sort of do.

So with what FFG said, anything produced by FFG could be and in a way should be considered canon, because Disney said all the new stuff would be. The fact that it was started prior to that doesn't IMO anyway change anything.

The Vigil was a fully-rendered CGI 3D created ship that was made Canon because it was included in the Essential Guide to Warfare.

That's pretty big for the vigil if FFG is recognizing it and putting it in Age of Rebellion. Didn't it start as just a fan made render?

Yep. It was a fan model, and then the artist put a small and blurry shot of it in the background of an image they were commissioned to do for a licensed product, making it canon. But I don't really understand why anyone is so interested in seeing more of it. It's not a bad design, but I'd rather see something with more history behind it.

People want to see it because it's a dagger shaped Imperial capital ship of the correct size to be used in this game. It is the only ship that meets that criteria.

I can't imagine there's any Imperial players out there that don't want their own Star Destroyer, even if it isn't technically a Star Destroyer.

It's the perfect ship, but seemed unlikely because of how obscure it was. But between them including a ship as obscure as the Decimator and the Vigils inclusion in Age of Rebellion it's seeming more and more likely.

With the Gozanti in the Rebels series I"m sure we'll see that too though.

I'm looking forward to Gen Con and their possible announcement.