To see if a non Apple based charger which supports USB Power Delivery like the AUKEY PA-Y7 USB Type-C Wall Charger can work with the Apple 15" MacBook Pro (Late 2016), we will observe how they perform here with the Mac's battery being well charged.
The AUKEY PA-Y7 USB Type-C Wall Charger initiates USB Power Delivery communication with the Mac by declaring its source capabilities of 15 watts (5 volts @ 3 amps), 27 watts (9 volts @ 3 amps), and 29 watts (14.5 volts @ 2 amps). The Apple 15" MacBook Pro (Late 2016) then requests to draw 29 watts (14.5 volts @ 2 amps) from the charger which it accepts.
While the Mac is being charged on an already well charged battery, we can confirm that the power drawn is initially 14.5 volts @ 2 amps but the current drawn steadily drops as the battery becomes fully charged.
While you can't charge as fast as using a 85 watts charger, the 29 watts based AUKEY PA-Y7 USB Type-C Wall Charger still charges fine with the Apple 15" MacBook Pro (Late 2016) using USB Power Delivery.