^ Well I did say test bed for new technology in general. Like it could have space for testing of VLS and other tech like the PLAN's test vessel which we've seen with new radars and HQ-10 being fitted on etc.
(and for the record I believe there was a "downsized" 022 which was launched first and probably acted as a "tech demonstrator")
wrt the stealthy design -- there's a good chance the investment into this submarine's shaping could be applied to a real class of SSKs.
I remain unsure of what this sub could be for, but I wouldn't rule out the idea that it can be a dedicated test boat.