Two connections on a device is nice to have but I doubt a lot of streaming boxes will have it. Luckily, at the moment there aren't many services doing 4K with lossless audio. Plus it defeats the one HDMI cable to everything approach.
Here is an HDMI rant for fun. IMHO I think HDMI from the start was a very poor standard pushed on consumers. First it was never designed for expandability or practicality. Practicality first. Who would design a non-locking connector for a device. A cable that can't be cut and a new connector attached, none of these engineers that designed this must not have ever ran cables through a wall. And limited cable length before you lose signal. And even shorter lengths as bandwidth increases. A computer guy whos monitor is 3 feet above his computer must have designed HDMI. Oh wait it did get built off DVI
HDCP are they kidding! When was the last time people connected two VCRs together to copy something. That didn't even happen with component cables. HDCP should have realized in the digital age, people hack the disc or the hard drive. They don't copy between devices anymore. HDCP is totally unnecessary and only added problems to HDMI
Now the expandability. When HDMI was designed 1080P/60 used about 4.5gbs so they made HDMI to go up to 4.95gbs. They couldn't predict that greater bandwidth would be needed in the future
I knew it back then, but who am I. But people like Joe Kane knew it and talked about things like higher frame rates, greater resolution, greater colors, 3D, better bit depth, etc. If I were making a standard for cabling I would want to have a lot extra in the pipeline for future expansion, probably at least 5 times the bandwidth needed in the current day, preferably 10 times the current highest bandwidth format.
Some might say that the technology didn't exist about 15 years ago to do the things that might happen in the future. In reality it did. Fifteen years ago we already had technology that could handle more than the 18gbs used today and it didn't have the practical problems of HDMI. That technology is called fiber optics. It has been around for a long time.
Now if HDMI could have handled say 20gbs or 100gbs from the start there would be no problems with sound bars taking off the audio and sending the video to the display. You wouldn't have to upgrade the sound bar if you got a new TV and 4K device. Or have to use two HDMI cables from a device to get the best audio and video. Unfortunately, we are stuck with it.
Hope you enjoyed the rant