Sounds like an interesting project. What they describe sounds similar to the I2C hardware ... the first thing it does is check the device address in the first byte.
However there is nothing stopping you having a protocol yourself where you send an address followed by data, with something like address 0 being "all do this".
In fact if you use the packet structure I described in my link, just make the first byte of the packet the address. Each device decodes the packet, and if not addressed to itself, ignores it.