No, not yet.
The Proton C is based on ARM, and offers some advantages over the Pro Micro and Elite C - especially better performance and more flash memory, which enables you to work with your firmware more freely if you're a power user.
However, the part of QMK that lets split keyboards work does not yet fully work with ARM.
In the meantime, my advice is to use an Elite C if you wish to use USB C. If you wish to upgrade to a Proton C in the future, you should consider socketing your controller with Mill Max Sockets so it can more easily be replaced.
The QMK Proton C, image courtesy of qmk.fm.