Unfortunately this is not new news. but perhaps good news for current and future WF-1000XM4 owners. Recalling back to the WF-1000XM4 teardown post, we know the internal battery is a 3.85V coin cell. This normally would not be an issue except finding the Springpower 3.85V battery is near impossible right now. There may be some links on the web, but they seem sketchy and who knows what you will receive when you order it.
Another Sony wireless headset has appeared on Bluetooth SIG, code YY2966. The Bluetooth version is 5.2 but looking at the supported layers, there is no support for "Isochronous Adaptation Layer", which is indicative of LE Audio. So this might end up being either a low/mid level device or perhaps an over the ear headset where LE Audio is not as important versus in a small in-ear headset.
A new wireless headsets from Sony has appeared on the FCC, the YY2958. In an earlier post I wrote that this code was still unknown and could have been a new headset and it turned out this is the case. The new headset is the WH-CH520, replacing the older WH-CH510.
A week ago Sony released a firmware update for the WH-1000XM5, and reading through some reports and user experience it appears that the NC issues caused by the Auto NC Optimizer may have been solved.
Thanks to an anonymous comment on the previous post, we now know what the YY2962 are, the Sony Off-Ear headphones, or WI-OE600. The product post can be found on the Indiegogo page, but the campaign closed last year. Unfortunately it was only open to Japanese and US individuals only, so I could not have ordered one, even if I wanted to. Fortunately, the campaign was very successful, so perhaps Sony will put the model into mass production in the future.