I believe that this is the first time we’ve seen an operational J-20 without luneberg lens. Was it carrying out patrol operations?
They really shouldn't be risking the signatures of the J-20 with patrols anywhere near Chinese eastern borders. It could be nearer to India or well within China.
Plenty sure that PLAAF would have flown J-20 without LL in many operations and exercises that weren't broadcasted publicly. Maybe it's just the first instance where it has been. I still doubt this would be near eastern borders where Japanese and Americans have eyes and ears switched on 24/7 for things like WZ-8, J-20 and so on.