Thanks for the reasoned reply, hlccThere are not too many examples, but F-20, F-15 Silent Eagle and to a lesser degree some of the advanced F-16 variants comes to mind.
After appearing in the much higher profiled Paris airshow & Dubai airshow in 2015, appearing in the much smaller & lower profiled Bahrain airshow probably became highly redundant. Any country that's even remotely interested in JF-17 already got a good look at the aircraft in those 2 other air shows.
Sure, i guess those types you mention are more developments/variants of aircraft in service.
And, the JF-17 didn't appear at Dubai 2015. That was the first of the two it was billed at, along with Bahrain, where it didn't appear for some reason.