I should have said 5V, 9V,
15V and 20V, not 12V.
My information comes from articles such as your link and much hands on experience of three 12" MacBooks and two 13" MBPs. I have different USB-C docks (not hubs) which supply power to the laptop, USB-PD battery packs, various Apple USB-C PD chargers and third party USB-PD wall chargers like the Atom that I linked. Importantly I also have a
Satechi USB-C power meter which shows the voltage and current that is actually in use.
I just measured a few I have around, plugged in to my 12" MacBook through the Satechi meter. As far as I can see the wall chargers and Docks all use 20V1.5A and the Battery packs 15V2A. At some point in the past I am sure I had a 9V3A device but don't seem to have it now.
Apple 30W:20V supplied with the MacBook
Apple 87W: 20V normally supplied with 15" MBP
Plugable USB-C Dock: 20V
Anker Atom 30W:20V
RavPower 26000 USB-PD battery pack: 15V
Anker 26000 USB-PD battery pack:15V
Caldigit USB-C Dock: 20V
Anker PowerPort USB-PD: 20V
Satechi USB-PD wall charger: 20V
Think that Lenovo would use the 20V profile.