Probably a corruption of the fact that the protocol to get HDMI out of the Switch is a proprietary alt-mode, which is why standard docks and USB-C to HDMI adapters don't work. But USB-PD chargers are very much intended to work.

The docks that do work generally reversed-engineered the proprietary protocol, and some have damaged Switches because they got details wrong.

The protocol to get video-out isn’t proprietary, just rare —they’re using Mobility DisplayPort from the Switch, and converting DP to HDMI in the dock.

Of course, had they used the native HDMI side-channel (which I’m not sure had been finalized at the time), they would have been able to skip this step.

I think I'm wrong, honestly, given the two replies to my two comments on the matter. It's too late to edit them but I am upvoting those replies anyways!

I do think there's still the matter of "Not all USB-PD adapters provide the specific electrical demands of a Switch or Switch Dock" to contend with — and that does tie back to the original article's point about USB-C being kind of a nightmare.

EDIT: There are still reports of someone frying a Switch with an Apple USB-C power adapter (which is USB-C compliant), no dock or anything involved. Whatever else does or doesn't work, Nintendo won't cover damage under warranty if you used a third-party charger.

The port is USB-C but the power and data follow a custom protocol.

I would assume that you are not allowed to call it USB-C if you don't pass the USB compliance process, which I would hope ensures that the protocol is implemented according to standard.