Yes, there are probably a number of reasons why Crown owners have been silent. Some of it comes down to, dare I say, burnout on FX Hype and accuracy! I think the Impact did a lot of that. Phenomenal accuracy (Impact) with even more phenomenal accuracy for the Crown.
The Impact was a jump of light years in design. The Crown is better (IMHO) but only incrementally better. Both are phenomenally accurate. The Smooth Twist X barrel is based on the Smooth Twist, and only incrementally better. That quantum leap just isn't there.
FX made the accuracy news so much, people just expect it. If they made a bad gun, that would get massive press, but making another phenomenally accurate gun just isn't news for FX (pretty sad, isn't it?)