To hell with THAT theory, I know for a FACT that this ban will be useful.
I work as a Customs broker, and thus receive calls from many trucking companies... their dispatchers and drivers.
There are multiple trucking companies that spoof their caller ID for... I can't even begin to guess what reason. One of them shows up as "123456" on our caller ID... I can't fathom what use THAT is. There's another one that uses something random, can't recall what offhand.
And another one... the actual trucking company of which I'll avoid mentioning... actually has "911" show up as its caller ID. I've thought that there's no WAY that can be legal, pretending to be 911 by way of caller ID. I've come to guess that the reason they do this is that there's... I dunno... a better chance of whoever they're calling not letting it go to voicemail, or perhaps just being picked up faster? No clue.
So yes, there ARE legitimate companies that spoof their caller ID to either random digits, or outright entirely different things. And that 911 company? This isn't some small, mom-and-pop type operation either... we're talking hundreds of offices all over Canada AND the USA. If they were forced to NOT masquarade as an emergency service, it'd be REALLY nice.
I've debated somehow reporting their caller-ID spoofing, but never came up with a good place to report to. They, as I said, have many offices, only one of which is in my city... and that's not the one that calls us to check their shipments anyway.