This has been a thing for quite a while with Comcast. It is also available to a customer service rep. It is retrieved from the Gateway via SNMP if I'm not mistaken. Customer service reps can also reset your wireless password either to a default or a specific one of yours or their choosing if necessary.
This is something to remember with cable modems and especially gateways. As long as it is connected to their Network it is practically thiers from a configurations standpoint, they are in complete control of the device and can get any information they need or want from said device.
I'm not saying they are doing anything nefarious or packet capping the local network or anything of that nature that is a little on the tin foil hat side for me personally, but you should always consider that any information available to a cable modem Gateway or plain cable modem is available to the ISP.
As many have recommended in the past always get a separate router and a plane modem.
Brandon Jackson