Aside from the revelation of using Google Widevine ( I had not seen that come up in the other threads/chat on the topic) there is nothing new there with this "update". However, that link is a new thread, much more straightforward with info.
All SD been saying for more than a year now, buried among hundreds of posts and pages, is they are waiting for the A3SA servers to work to give them the certificate or whatever. They can do nothing, and have done nothing more, just waiting.
Meanwhile, other products, well, at least one other, that is mentioned other places, but SD auto mods removes mentions of it, works fine for DRM playback. But, i do not think that is a Gateway type device. This and other other STB type box, i think, also mentioned on my local OTA thread on AVSForm.
I, and many others, given up/stopped caring about DRM support for HDHR/ gateway devices. Highly doubt it will ever happen.
Fact is, at present time, if you want to watch DRM ATSC 3.0 channels, you have to buy a tv with built in 3.0 tuner, or buy one of the 2x models(i think) STB type decoder/adapter boxes that support DRM.
I recently got a Samsung TV, that has 3.0 tuner. hooked up some super cheap antenna i had lying around. Can view my 2x DRM station now... whoopie . One of them is locked into HDR, and looks like crap to me, and the other, has been reveled to be 720p source broadcast that is upscaled to 1080p, so, it not look any better than its 1.0 version. The TV also seems to not pull TV Guide data for ATSC 3.0 well, often it just says No Data...has data for the 1.0 versions.
Hopefully, like FOX did in my area, other DRM protected stations will eventually drop DRM, but, don't hold your breath.