How extensive do you think this standard will be? Will all J-11Bs eventually receive the BG upgrade?
To put my $0.02 in, I don't think it's meaningful that we haven't seen a J-11BG fitted with PL-15s (we seldom see them armed to begin with). If the electronics have been upgraded, then it would be shocking if the newest armaments haven't also been integrated.
More likely the entire fleet will be. Sooner or later so will the J-10B.
What's more interesting is the route they can take on this.
A.) Replace the radar entirely. They take the existing one out, and replace it with say, the entire unit from the J-16. It turns the play into essentially a single seater J-16 but lacking the functionality of the second operator. The most expensive method.
B.) Assuming the radar is modular, and it may likely be, you only replace specific parts of the radar. You replace the slotted array with the AESA, and then the back end boxes of the radar. Other parts of the back end are retained. This is cheaper and faster to do, but not as fully optimized as the A.) route.
If you want to commit to the costs of going AESA for your fleet, its best to make it your entire fleet. AESA modules are expensive in small quantity, so you want to make as many of them so you can drive the prices to the floor with volume. That's why I say they should upgrade the J-10B fleet too. The more upgrades you do, the cheaper it becomes for each and every plane.