bit_user :
I assumed this was all about cutting costs so that PSVR could be bundled with Pro. But, so far, the only bundles I've seen are with the non-pro PS4. So, maybe Pro isn't as much about VR as I thought.
It's not a cost saving decision. It would save them like a nickel. All the decoding capabilities are there. PS Pro IS about enabling better VR experiences, but they aren't likely to bundle until they're able to bring costs under control.
bit_user :
An alternate explanation might be Sony's big push into online streaming. Maybe they see demand low, as the BD 4K disc market is small, and would rather stream you 4k. Sadly, their decision to omit 4k disc support will help fulfill the prophecy of few 4k titles.
THIS is the bigger reason. They released UHD, but all the studios charge WAY too much for UHD titles, including Sony. This may have to do with Sony Blu-ray licensing costs. Then the players were insanely expensive. Plus they're pushing 4K streaming hard. When it was first released, the Xbox One S was the cheapest 4K HDR Blu-ray player, only recently undercut by budget models (and even then only by a tiny bit). Whether it's intentional or not, Sony has done all they can to murder the UHD disc format in its infancy.
Personally I do stream a lot, but when it comes to movies I really like, I do buy some physical media. I know some movie buffs that bought 4K HDR TVs and XB1 S specifically for UHD BDs. So you're not the only one out there... but it is getting rarer. Most people either stream, or they buy discs but they look for cheap "good enough" BDs and DVDs even.