Who knows - as mentioned they could limit its implementation e.g. just the GPU slot so may negate need for fan (always the caveat ) - and would be an added selling point for the boards without treading on x570 features/sales (although wouldn't be missed.).I think B550 is going to be limited to PCI-e 3.0, no 4.0, to get the costs down, so they probably wont need a fan,
For some it's an added irritating, potential point of failure not just the noise - although semi-passive should eventually be feature on more boards (certainly Gigabyte via BIOS updates - from what i've read).the fan isnt noisy anyway, mines always running at 1200rpm and I cant hear a thing.
That's the rub - very limited test and only one mans conclusions. But, if relying on that data alone (which you shouldn't) it does imply the average user doesn't need the fan at all. But, again i stress only one mans review - too smaller pool to draw any conclusions. You also have to factor that they've cut a large chunk out of the PCH heatsink to make way for the active cooling to be neatly slotted within, in a lot of cases, which may hamper mine/users wish to experiment without a fan.as for the above video.....what if your running all 3 nvme slots ?
Hopefully, more users will upload their results/experimentation - and we'll start to get a truer picture of what the state of play is...