Probably with good reason too, since if I'm understanding the US system correctly proposed regulations are created by unelected officials and can come into effect without any congressional vote whatsoever. Allowing filibustering of CRA votes would mean that regulations could be created despite the majority of the Senate and House strongly opposing them.
Not really -- rulemaking from the executive branch agencies is supposed to be what takes laws and implements them into concrete policy. The CRA is supposed to allow Congress the ability to void the rules that are perceived as going against the spirit of the law that was passed.
I haven't seen any reporting on a specific law that these rules were tied to, but I have seen references made to laws predating the public internet that mandate privacy on phone calls that.
