Shouldn't 2001 and 2002 be mothballed by now? After all, there are a number of differences between them and the production version.
No Sir, I do not believe they will be taken off of flight status until there are sufficient number of aircraft to finish up developmental flight testing. Two things drive my "opinion".
1. This is a completely new aircraft, absolutely a clean sheet, though possibly borrowing some design elements from existing aircraft.
2. The proof of concept demonstrators remain substantially the same aerodynamically and engine wise, as the LRIP birds that are a building now. They have more inherent value in "flying off" hours and building developmental time on the J-20 overall, than they do as some type of "historical marker", although I am in total agreement that they are "historic". I can assure you they will not be parked outside on some gate, and it would not surprise me what-so-ever that they become the foundation of a museum collection some day!