I'll break this up into 2 chunks of Compatibility and Wireless Bandwidth (awesome speeds).
Compatibility. Cox owns a network of coaxial, fiber optic and hybrid fiber-coaxial (HFC) cables. To connect to their network, you'll need a Cox-certified device. The device for their coaxial network is a DOCSIS modem. The device for their fiber optic network is Optical Network Terminal (ONT). You'll need one of these devices.
It's not a question of Orbi being compatible with Gigablast. It's a question of you having a DOCSIS or ONT compatible and capable with the Cox network as well as your Cox Internet-plan. If Cox installed a Panoramic WiFi modem, I'll assume it's compatible and capable. That's how you connect to the Cox network.
Orbi, on the other hand, has to be compatible with that DOCSIS or ONT. If Orbi is WiFi certified with IEEE 802.11...it is...Orbi will not only work in San Diego, but also Caribou, Maine. It'll work.
The Panoramic WiFi modem is both a modem and router. If you return your Panoramic, you'll need to buy both a modem and router. Tiffany provided a link to certified modems, and you'll shop around for a WiFi-certified router, such as Orbi.
If price is a concern, we can help find a less expensive but equally powerful router.