My impression from the article is that what you're saying is in line with it: if you implement PD, you can do either.
It sounded like the line you quote was expressing suprise that baseline USB power supply in USB-C - without implementing PD - can't do that. But apparently could with older USB OTG.
Oh, I guess I understand now. When the article said "USB-C does not allow this", it actually meant "USB-C without PD does not allow this". And "always" in that specific paragraph also meant "without PD".
It sounded like the line you quote was expressing suprise that baseline USB power supply in USB-C - without implementing PD - can't do that. But apparently could with older USB OTG.