An interesting product I was not aware of.
the "GX" products are basically the central 'brain' that collates all the data from the various Victron devices, such as the BMV Monitord, MPPT Controllers, etc. The Colour Control GX (CCGX) was the first, followed by the Venus GX (which is what I run) which is a 'headless' CCGX with a few extra features, and there is the Octo GX, which is like a Venus GX with more physical connections for additional devices (you might use this if you have a whole bunch of MPPTs for example)
None of those have bluetooth capabilty so the only way for the user to communicate with a GX is via it's Network (RJ45 Cable, Wifi or Internet). Looks like with the Cerbo they have extended that connectivity to using the Victron Connect Smartphone app.
Is that useful? Given that I doubt if there is a single Smartphone/Tablet around that has Bluetooth but does not have Wi-Fi, I am not sure of it being a massive benefit (a nice to have for sure).
If it allows you to connect the Victron Devices to the GX via Bluetooth, then THAT would be a great advantage - I shall be reading further on that point

Also, the firmware that the GX systems run on is called "Venus OS" and is open source. I guess there will have been an update to add bluetooth support for the Cerbo - I wonder if that update will enabled the Bluetooth that is on the Raspberry Pi that runs Venus OS? I would think if not immediately, some clever chap will do the tweaks to allow it.