Viewing cameras remotely would depend on the connection type. If your camera connects to a system which is managed remotely then the connection isn't likely to be direct and it would work. You can connect to the system's management servers which are on the Internet and your system in your home is connecting to them as well. So it is a delegated connection, of sorts. If the device itself were trying to be exposed on the internet with its own directly-accessible IP address then that is what would be a problem due to CGNAT. I'd suspect most camera/security systems would be the former.
