Unknown in seems as not enough in the wild yet. Would venture that these initial drops are all WBC if I had to guess. If I recall a motherglass sheet can be made up of all 42" models so may be for now 42" all coming from same line which may be WBC. Suppose we will see with more samples in the wild. I would also venture the fact that they said the 42" and 48" for that matter are being limited in brightness means that its easy to sell them as WBC and as production moves all over the WBE later in 2022 just cap them to the same level anyways as HDTV test pointed out (the capping part that is).
I think the problem here is confusion. I think LG display uses the term EX. LG Electronics uses the term EVO but they do not talk about the panel itself, infact they have gone to pains from what I have seen of not confirming that all the EVO panels are EX panels. Rather for LG electronics, the new chipset and software algorithm's is enough to say its EVO.
All that said, a spanner in all this is, Vincent at HDTV test is suggesting for C2 now anyways, regardless of the serial number the code is the same. This is him comparing a WBE 48" and WBC 42" both share the same code at the end which most would assume to be a WBC panel, but using his tools suggest its WBE, so the serial number no longer clearly lets you know what panel you have. Combine that with it not being in service menu, your not going to know what you have unless you have serious dosh for the gear to check the spectral distribution yourself
I think reality of it is, as a user with a C2 whatever panel it has is going to be capped to perform at specified levels. the question is the longevity really.