While it's certainly tight I really wouldn't worry, on time and you're fine. This is one of those connections where if you're sitting at CLT and the flight to PHL gets even slightly delayed then just get rebooked straight from CLT, either on one of the nonstops or via LGA, etc.

And CLT would likely arrive into B or C, although A is sometimes possible. Plus PHL-YUL is mostly operated by ERJ-145's so boarding won't start until ~20 mins before departure, with all carry-on's gate checked, so there's no need to be at the gate on onboard early.