

HDMI has never been an open standard (to the best of my understanding anyway). You’ve always needed to be an adopter or a member of HDMI forum to get the latest (or future) specs. So it’s not like they’ve just rejected a new idea.
Okay not publishing the spec is still the same, but something else is new nonetheless.
AMD is an adopter*, they have the spec and they implemented a driver for 2.1 intended to be open sourced in Linux. But they were still blocked from publishing it. For HDMI 1.4 that wasn’t an issue yet from what I’ve found (though it’s always hard to search for non-existence). Open source implementations of HDMI 1.4, even in hardware description languages, seem to exist.
*you can search for “ADVANCED MICRO DEVICES” here to confirm for yourself






Not that many it seems… Ignoring extremely pricey ones, I could find the Lenovo ThinkVision E65 LFD for what converts to 1200 USD in a local shop. And even that is not really price competitive.