Which Montreal feed are you referring to?
That thread was from 2005, over 10 years ago. I think the question is referring to an old Montreal setup that doesn't exist anymore.
To answer the question, 10 years late, I seem to recall that 135.60 used to be a Terminal frequency, then they switched it to a Center frequency initially using it for high altitude airspace, then switched it again to a low altitude sector close to around 10 years ago.
135.60 is now on the current Montreal Center radio, it's the Center frequency you can hear the controller on (faint), it's cross-coupled with 126.575/133.900 and 128.775 and sometimes with 134.975, these are all low altitude sectors. As far as I can tell there are no high altitude frequencies on this setup.
It's unfortunate that they decided to keep the Montreal Terminal frequencies on the current Center feed as they are already being scanned on the other Montreal radio and are quite busy and block out a lot of the Center transmissions.