Switches are probably either cherry's low profile switch, or Kailh's version 2 of it's choc low profile switch.
I honestly have no idea why this was posted on HN, there's a ton of other keyboards that have the same specs and features. Sure it's got Logitech's priority dongle, but as you point out, what's here that's not on a 70 dollar gk65.
I think it was posted more as an interesting industry trend. It's acknowledgement of a former niche turning into a real industry from the big name in the space.
Which trend? I'm not sure I'd consider low profile a trend, and logitech has been making mechanical keyboards for years. They've even made other low profile mechanical keyboards.
I honestly have no idea why this was posted on HN, there's a ton of other keyboards that have the same specs and features. Sure it's got Logitech's priority dongle, but as you point out, what's here that's not on a 70 dollar gk65.