A couple of things to consider...
Commercial release these days does not necessarily mean Bluray / Disc. They could be planning a commercial release that would be purely digital even for the 4K, or even through a commercial streaming service like Netflix. In which case a DVD from the fan club might be the only physical version. I'll take any physical version over none. I like the booklets, and the photos and the credits.
And I was told plans for commercial release would be announced in March (if it was going to happen.) That was before this fan club disc was announced. But the fan club announcement says they will be letting us know about dispatch in February. That suggests to me that these fan club gifts would be well ahead of any commercial release anyway.
https://twitter.com/markpeterboro/status/1222463197560672256If you look at the poll above, done in response to the gift, 18% of respondents said they have a DVD player only, 49% said they have DVD and bluray, 15% said they can play DVD, bluray and 4K, and 18% said they can't play any sort of disc on their main television. That means that almost 18% are never going to get any use out of this gift. There's sure to be lots of copies around on auction at that rate. But if you sent it out on a quality other than DVD you'd double that and be sending 35% of the fan club a disc they cannot use. That's getting a little high. It's a small poll, but I'm sure there is information out there available to the band about sales, and formats, even from their own past sales. One of the biggest complaints they would get each time they have done a vinyl gift is that about half the fan club cannot even play them as they don't own a functioning record player (about 90% can play a cd.) So had they done a 4K disc that only about 15% could play, they'd have a deluge of complaints...
I likely won't watch this one over and over again. I watched Paris maybe twice. But I do listen to the music from it all the time. At least DVD will give me a disc that is easy to rip. I'm not heartbroken over this one...