Based on the proposal it seems like USB-PD is implied: (from page 10 of the proposal here)
New Annex (Part I): It requires that mobiles phones and the similar radio devices, if
they are capable to be recharged via wired charging, are equipped with the USB
Type-C receptacle and, if they also require charging at voltages higher than 5 volts or
currents higher than 3 amperes or powers higher than 15 watts , incorporate the USB
Power Delivery charging communication protocol.
I don’t doubt that there will still be room for vendor fuckery; “Ensuring a safe and reliable consumer experience just requires that our power management IC be vigilant in refusing to work with substandard chargers; why do you love electrical fires?”; and USB-PD is a pig of a spec with some notably subpar implementations(not all as good as the cables that kill devices if you use them, though those are an exciting option; but all kinds of weirdness); but it’s pretty clear that either you use the old-reliable of 5v and as much current as you can coax out of the source; or you use USB-PD.
Qualcomm will probably be a bit peevish, the “voltages higher than 5 volts” bit excludes basically all of their pet “Quick Charge” stuff, unless operating in 5v compatibility mode(for the erlier QC versions) or PD compatibility mode (for at least v4, and presumably v5).
