It's all good. USB-2, USB-3, USB-3.1, etc is the technology regarding data transfer speed. USB-C is the connector Vs USB-A (flat and keyed), USB-micro (very small, flat, and keyed) USB-B like for a printer or MIDI keyboard controller. USB-C is not keyed meaning it be plugged in one way or flipped 180. Very convenient and the market is shifting towards that direction i.e. Tesla Model Y is all USB-C.
The MK5 is shipped with both a USB-C ---> USB-C and a USB-C ---> USB-A cable, so you are good to go. The technology it is using is still USB-2 which is plenty fast for what it does.
https://www.sweetwater.com/store/detail/Ultralite5--motu-ultralite-mk5-18x22-usb-audio-interfaceIf you recall, Drew Worthen's big Hauptwerk install at Greenwood UMC is using two 24Ao units and 1 DAT for a total of 56 channels! All USB-2 technology. From my history here, it was the late Leo Christensen who was the godfather and crowning champ of a Hauptwerk multichannel setup having 72 channels! He pushed the limits of combining multiple MOTU interfaces prior to them adopting the AVB protocol. You couldn't find a bigger fan of Hauptwerk and he had a website with lots of excellent information that he shared. Unfortunately when he died everything just vanished! A few of us here were fortunate to download some of his published documents. Would love to know what happened to ALL THOSE studio monitors!
Danny B.