The audience for xblig was never huge anyway.
Microsoft were put under pressure by AAA studios to give big releases priority positions in the search results, basically making indie games second class citizens in the arcade store.
Considering AAA studios might pay a lot for licensing to release games on physical dvds in brick and mortar stores for xbox, and xblig published games paid $99 a year it's easy to see why they might have got a bit miffed.
As more and more move from 360 to xbox one, the audience will continue to decrease, I wouldn't bother with it if I were you and stay tuned for an xbox one equivalent.
You can change that might to AAA studios pay a license fee to MS and Sony to release on the consoles, there is no might about that fact.
I have a feeling the XBox One equivalent will just be the strore like it is on Windows now.