OK there are few things on this post which are interesting and confusing at the same time. First of all is the announcement. Initially I thought other news outlets were reprinting the story incorrectly claiming BT Sport was going to stream the CL final in "HD HDR". But if you read the BT Sport original story you can clearly see they meant to say "HD HDR" not "UHD/4K HDR". HD and UHD/4K relate to the resolution of the video whereas HDR relates to the colour and contrast improvements done as part of HDR. The key is on this sentence: "And in a world first, BT Sport subscribers will be able to watch the Champions League final in HD High Dynamic Range (HDR) on the app, ahead of the launch of 4K HDR later this year". OK that's pretty clear so it's HD HDR not UHD/4K HDR. The second thing is that is clear the HD HDR transmission will be for "direct" BT customers via their mobile, Apple TV 4K and TV apps, so this does NOT include VM customers which get BT Sport as part of their TV package. Then if you keep reading the article it says: "BT Sport will launch its new 4K HDR service – enhancing the HDR picture resolution from high-definition to ultra-high definition – ahead of the new football season at a cost of just £5 per month."
That's all that's clear from that announcement. Now the parts that are not clear. First it's not clear which HDR standard BT Sport it's going to use. There are 3 main HDR standards: Dolby Vision (DV), HDR10 (and its new version HDR10+) and Hybrid Log Gamma (HLG). DV provides the best quality but it's not royalty free so Dolby gets a cut. Because of that it tends to be used by premium content such big budget movies and TV series. Both DV and HDR10 require some heavy processing to add the additional HDR data which makes them harder and costly to use in live transmissions such as live sports where you must post-process the video feed in real time. For that reason the BBC and NHK developed the HLG standard which provides decent HDR quality output but requires less computing power so it's more suitable for live transmissions. As I said BT Sport do not say which HDR standard they will broadcast their new 4K HDR service but given that they clarified it will be visible on the iPhone X and Apple TV 4K, which only support DV and HDR10, it points to one of those standards. Having said that it could also be a new standard that they can control from their own apps, although that's unlikely. It also worth noting that not all 4K TVs support all the HDR standards. Most notably Samsung doesn't seem to support DV as don't want to pay the royalties. There are however some 4K TVs that currently support all 3 HDR standards, like the LG OLEDs. It also unclear whether Virgin Media will be allowed to offer the new 4K HDR service.
What's clear though is that the Virgin Media does support 4K HDR content as ozsat and tony have said. Virgin Media is currently broadcasting Roland Garros in 4K HDR. To see it you need a V6 box, access to the Eurosport HD channels and a 4K TV that supports the HLG HDR standard. If you meet those requirements just tune to Eurosport 1 HD or Eurosport 2 HD while Roland Garros is live and press the red button. You will then be switched to the 4K HDR signal. Below are some pictures I took tonight. The first one shows Eurosport in 4K and the second shows my TV's HDR message confirming the video is using HLG HDR.
So in summary I don't think the Champions League final will be available in HDR for Virgin Media customers since it's only available for BT Spotfire direct customers via their Apps and it's only available in HD HDR not UHD/4K HDR. It's unclear what HDR format BT Sport uses for their CL HD HDR transmission and what format they will use for their 4K/UHD HDR service when it launches but I suspect it's going to be HDR10. Given that BT Sports will charge their customers £5 extra for the new UHD/4K HDR service I doubt VM customers will get it for free. It's also unclear if BT Sport will make the UHD/4K HDR service available to VM customers. But considering that VM is already doing UHD/4K HDR transmissions for Roland Garros I don't see why they couldn't do UHD/4K HDR HDR10 transmissions, if that's what BT Sport it's going to use. They also have BT Sport in 4K that BT Sport don't make available to Sky so we shall see what they do...