The good reason is that there are plenty of third party boards that already offer what you want. There’s very little to be gained by an ‘official’ one. The next one probably should have C, if just because it is the Euro standard, but no urgent need to backport.

While we're at it, their reference board also doesn't have a reset button, it just has one for boot. It's perhaps one of the most inconvenient official dev boards I've ever used in modern times.