There's a much more immediately practical reason to keep it in-firewall as well: if the utility company accidentally cuts a fiber line outside my house, I don't want to be suddenly unable to turn off my hallway light.
Wait, so now building codes are going to get involved with what I run in my house after it is built and inspected? That doesn't sound like building codes. If anything, regulation from the FCC or someone else would be more uh, fitting.
Sure, I was thinking of things like lights supporting local control. I guess I'd try to write it so that a phone app talking to the light counted as passing the rule, as long as it worked without an internet connection.
I don't see how it is a problem for simple rules like "Installed lights must always be controllable from inside the premises" to be code.
The companies aren't going to do it without regulation.