Given that hardly anyone is doing USB 3.1 Gen 2 headers, regardless of form factor, I think it's going to be while before we see 3.1 Gen 2 USB-C appearing on many cases of any size. I'm certainly in no rush to see them introduced to the M1. I have a couple of USB 3.1 Gen 2 ports (USB-A, not C) on my motherboard's back panel, and they're perfectly adequate, and loads of USB A to USB C cables and adapters, so I can live quite happily without front panel 3.1 Gen 2 USB-C.Just did a quick survey of Z270/Z370 ITX boards:
So it looks like it's still just Asus that's including the Gen 2 front panel header.
Last that w360 looked into it, the production for Gen 2 front panel cables was all booked up.
One thing that does occur, though: do front panel USB-A ports exist that can be hooked up to the USB 3.1 Gen 2 header on the Asus boards? That would at least give USB 3.1 Gen 2 front panel functionality, and users could just use an A to C cable if required.
As an aside, I hate the USB naming convention. USB 3.1 Gen 2 is so clunky and I've got sick of typing it out just making this post. You can't just say "USB-C" instead, either, as USB-C is just the plug type rather than a speed standard. And don't get me started on motherboard manufacturers and their individual naming conventions - some refer to USB 3.1 when then mean USB 3.1 Gen 1, others use USB 3.0; some use USB 3.1 to mean USB 3.1 Gen 2. Then some mention USB-C when they mean USB 3.1 Gen 1 type-C, and finally some talk about USB-C when they mean USB 3.1 Gen 2 type-C. Such a terrible, terrible mess