Don't you need to be really careful with which chargers you use with each device, regardless of the cable type? Pretty sure USB-C headphones shouldn't be charged with a USB-C Macbook Pro wall charger.
Unless explicitly negotiated by both ends, every USB-C charger outputs the same boring 5 volts as classic USB, so the headphones should charge just fine.
The switch dock demands 39 watts, which implies 15 volts, but the switch itself will negotiate any voltage when standalone.
In fact, I am doing it right now.
Output on the adapter reads: 5v@1.5A/15v@2.6A
The only time things break is when you attach a broken charger that outputs 9 volts onto a wire that's supposed to be doing 2 volt signals.
That should be fine. There's a protocol for the charger and the device to communicate and decide what power to charge at.
Also some devices don't support anything else but USB-A to C cable that comes in a box. That's why I returned JBL Charge 4 and got Anker Soundcore Motion+. Much crispier stereo sound at expense of some base.
Unfortunately a lot of devices are out of spec like the Nintendo switch which can be damaged by an in spec charger.