There's no inherent reason why it should be worse than either the LS50 Wireless II or KC62/KF92.FWIW, Stereophiles review of the LSX matched Kefs manual regarding buffer time in wireless mode. I confirmed latency basically evaporated in wired mode; it's reasonable to expect similar here although I'd hope wireless latency to have decreased at least a little given advancements since that time.
The KEF LS50 Wireless II white paper says the maximum latency is 6ms (which would be with phase correction on, and the wireless link). I'm going to guess it's about 3-4ms with phase correction off (based on Genelec's numbers for the option).
I don't know what the KC62's latency is though. I've seen a couple of sources say 0.5ms, which I'm sceptical about. My own KF92 calibration has it about 5ms ahead of the mains.
So I'm going to say 6ms worst-case, maybe better.