When will be be able to craft Stillwinds again?
Whenever they decide too.
Not for a long while i bet. They gave us stillwind access in the event that just ended.
I got upgraded Stillwinds when they were introduced. I thought they sucked, so I sold them.
Can you say REGRET? 
Lesson learned - don’t sell any weapons, modules or cabs. The nerf/buff cycle is an unforgiving monster.