Yesterday, Nintendo pushed the new 4.0.0 firmware update for the Nintendo Switch. While the new update included features like video capture and account transfers (to another Switch), one feature snuck into the update unannounced: support for wireless USB headphones.
Confirmed by multiple sources (and tested in this video from our colleagues at NintendoLife) the Switch now supports USB wireless headphones for both docked and handheld mode. Though there are some caveats.
Wireless USB shouldn't be confused with bluetooth headphones, which as far as we know still doesn't work with the Switch. Instead, if you have a wireless headphone that has a USB connector like the PlayStation Gold Headphones, you'll be able to plug in the USB receiver into the Switch dock while in TV mode and get wireless audio that way.
For handheld mode you'll need to use a USB-C adapter dongle. While it seems a little more tedious than just using a wired headphone, you can attach your wireless headphone receiver through the Switch's bottom USB-C port and get wireless audio that way.
Mic functionality is still up in the air, so don't expect this update to be a replacement for the Nintendo Switch voice app just yet however.
Frankly, it's a little weird Nintendo didn't choose to advertise this feature when the firmware update went live yesterday. Wireless audio while in dock mode is actually a pretty useful feature considering the standard docked control scheme doesn't include an audio jack for headphones by default.
It begs the question, what else was included in this update that Nintendo hasn't told us about?