I hope this rumor is true. Personally, I'm ready to buy several units as soon as they hit!
All the people arguing against it should grasp that more-capable hardware can still play less-demanding software to it's fullest. In other words, all happy with 1080p or 720p or SD will still be able to watch those formats on a 4K

TV. The iTunes store will still have lessor file format options to download- just as it does now. Your bandwidth demands can be exactly the same if you just stick with whatever size files you stream now. And so on.
Even more simply:
a 4K
TV forces nothing on anyone happy with the "as is." You might as well argue against hardware advances in iPhones, iPads & Macs too because you are satisfied with the "as is." What a 4K

TV will bring is more

TV buyers who refuse to buy one capped at 1080p now. More buyers helps us all.
The iTunes store content argument is practically ridiculous. If we wave a magic wand right now and make EVERYTHING in the iTunes store have a 4K version for

TV, how much money can any Studio make? Nothing. Why? Because hardware must exist to play advanced software. Your iPhone can't run software dependent on iOS11. Your Macs can't run software dependent on macOS <next>. Loading the iPhone or Mac app stores with software that can't be consumed today makes no sense (or $en$e) until iPhones & Macs are advanced enough to take advantage of it. This is no different. Hardware must always lead or, at best, launch with a collection of software capable of taking advantage of the advancements. This will be no different.
I am consistently dazzled to see how passionately some of "us" will argue against Apple advancing this ONE product, when just about every other thread for every other Apple product craves the future now. "We" have been coveting a "10th anniversary iPhone" for a couple of years now, longing for it to bring hardware features that do not exist in any iPhone available now. We covet software apps to take advantage of those hardware advancements even though there are zero such apps in the app store today. We want the latest & greatest in new Macs even if there is little to nothing to take advantage of those advances. "We" even argue on behalf of Apple in support of hardware "advances(?)" such as embracing USB3C or jettisoning the headphone jack well before there is much to take advantage of either.
But here- with this ONE product- "we" will passionately spin anything & everything in support of sticking with a status quo established years ago... even when all competitors have pretty much moved on to 4K... and even when pretty much everything else from Apple touts 4K capabilities as selling points. I'll conclude by summarizing the issue with a simple chain...
iPhone shoots 4K -> Apple movie editors edit 4K -> QuickTime plays 4K -> iTunes stores 4K ->
TV -> 4K Television
And if you happen to have a 1080p TV at the end of your own chain, no problem: more advanced hardware can downscale 4K video to maximize your 1080p picture OR show 1080p content at it's maximum. There is no effect at all on the "happy as is" people if Apple corrects the one broken link in that chain.