By releasing upgrades specifically targeted at a Legendary ship, FFG have pretty much laid to rest the notion that Disney won't let them revisit the E-Wing.
Or maybe Disney is telling FFG to hold off on the E-Wing because Disney wants to reintroduce the ship into the Canon the way they are the Defender.
Or maybe the design team at FFG is so taken by the new Canon toys that they're not exited about the E-Wing.
Or maybe they can't figure out a good way to buff Knave and Blackmoon without making Corran a god. I'm pretty sure the release of R-3 was an attempt at doing exactly that, but it didn't quite work.