No, the Netgear CG3000DCR is just a plain wired gateway. If you need wireless, and don't want to deal with adding your own WiFi router, call 1-800-391-3000, select technical support, and ask to be swapped to a Cisco DPC3939B; that model contains 2.4GHZ and 5GHz 802.11n capabilities. Be aware that this requires a technician visit to replace, and MIGHT carry a $99 installation charge (although I have had luck getting that charge waived. YMMV)
That's technically true, if you are renting a Cisco DPC3939B gateway.
I agree, it is not clearly explained on that page, and even if it were, you would still have to know in advance to ask the install technician during installation for a WiFi-enabled gateway. You are not the first person I have heard of who has had this particular situation happen.