When this dissolved gas issue is a problem on the large scale RO systems that I deal with, the typical course of action is to run the treated water through an air-stripping tower to help remove those gases from the water. An air-stripping tower is a column filled with very porous media in which the water enters the tower at the top and flows downward while air is blown into the column and exits at the top. The high surface area of the porous media provides high contact with the air and the gas is exchanged from the water to the air.
By the way, I just checked my home RO water. Current TDS reading is 20 ppm and the pH is 8.1. I've never checked the RO pH before and am surprised it was so high. Yes, the meter was calibrated prior to use.
I'll have to keep a closer eye on this RO pH thing in the future to see if my supply varies.
interesting. my RO water reads about 10-12ppm on TDS, and has PH around 5.6.