Sorry about that, we're going to update the info very soon, also we did some last minute changes to the packaging which wasn't finalized yet but now is to achieve even more power supply pin pad area.

Tomorrow a new version of the datasheet will be released with the required information!

Btw, IOs are all 1V8 and there's a pin for VREF (but there's no info on it in the first verisone of the datasheet yet).