As I understand it the following happened, in order:
1) FFG has stopped dealing Wings of War at Nexus' request. 2) Nexus went out of business. 3) The original game author(s) have gotten the rights to Wings of War and are looking towards working with a new publisher and wish for future iterations of the game to be backwards-compatible to everything on the market now.
I don't know if/when Wings of War will get picked back up. There's hope.