XB7 login

When I go to log in to a residential XB7 gateway at https://10.0.0.1 it prompts me to change the default username and password.  If I do that will Xfinity support still be able to log in to the gateway as well and check diagnostics and line signals as they have been doing recently to troubleshoot my service?  I don’t want to lock them out.   I just want to get in there and create a reserved IP for a printer MAC address so it always gets the same ip from DHCP.