I don't see why that would be the case. The language has been public for less than two years, and I don't see any reason it wouldn't become widely adopted for situations where it's a good fit.
Not so, every years students and millennials are graduated and users are relied heavily on mobile on the move and oversea. Get ready to watch WWDC 2016, the demand is still very much active.
Actionscript did open source, it create lot of unhappiness in the community and poor IDE performance but Swift is a different story, I'm looking forward to have Swift for server as long as the vendors contribution are growing, MS could be keen.