There was a part of me that was believing that "Avista" may have become the next gen Camaro...
GM brass probably signed off on the Avista to garner some attention for Buick, knowing full well they would never build a Buick "pony car" or sport coupe. But what I think they wanted more was to gauge reaction to its overall design... Which would've been used, more or less, for the next gen Camaro. Then the Avista went out and gained waaaayyyy more attention than most any other concept from any manufacturer this year.
I believe the Avenir was designed originally as a Holden, as was the Avista. But then they were given the green light to be built as Buick concepts, as Holden manufacturing was known to be coming to an end, and the era of Holden Opels/Buicks was underway. I also believe it is very likely that the Avenir was shelved so as not to compete with the CT6 (at a lower price), but also so it wouldn't possibly kill the CTS, with which it would probably share its pricing.
I think think the attention Avista has garnered is the same thing that will ultimately kill it. That is, I believe that GM would build a production version for Chevrolet under the Camaro nameplate, and piggy-back sales to Holden (Monaro?) from U.S. production, but would never build a Buick sport coupe. But Avista has garnered far more attention than most concepts, with Buick receiving more buzz from social media, fans of sporty/sports cars all over the world stating how they would fork over whatever Buick wanted to charge for the privilege of owning an Avista. Now Avista = Buick, and there's no way an "Avista Camaro" (or Monaro) will ever see the light of day, as I simply don't see GM green-lighting production of yet another Alpha vehicle (a coupe no less) that will compete in the $35k-$60k markets... Their reasoning would be that the car would steal much needed sales from Camaro, ATS & CTS, which it probably would. But it would also steal from other manufacturers as well.
And that's pretty much where we stand: Avista is too ingrained as a Buick to become a next gen Camaro, and with production already in place for the Camaro, ATS & CTS, there's no way that an Alpha Buick coupe is going to be introduced any time soon (read: never). "Avista," as we know it, is probably already dead... But it may well serve as the baseline to the design direction of the next gen Camaro... That is, I think the next Camaro will be a fully modern design, with few if any retro bits, which it doesn't need...