Instead, it looks like the IETF will be the one solving it. https://datatracker.ietf.org/wg/capport/documents/

Yeah. The wifi alliance track record is so bad that it's a real pity they run one of the most important protocols we have today. They are decades late on most required innovations, and when they try to design something, it's just so severely broken that requires many iterations to get to a decent status. Miracast is another example of being late and failing at producing something decent.