Does Alarm Pro Router need to be the primary?

We're considering purchasing the Alarm Pro system and also the latest doorbell camera. The website states, "Alarm Pro is designed to be the primary router for your home. It should not be added to an existing wifi network." Comcast is our internet/TV provider via a modem, i.e.. So I shouldn't plug the Alarm Pro into the Comcast modem? A RING rep to disregard that message, that the Alarm Pro doesn't need to be our primary router. Confused? Any input is appreciated.