Even today’s voice communications are transmitted on a separate “pipe” than data, as VZW’s voice is over its 1xRTT network, and most data is over its EvDO Rev A or LTE networks. Yes, spectrum is a concern, but how much when they are functionally separate? As you said, 1xRTT is digital, not analog, but they still aren’t IP packets on even the same network from what I understand.
This article makes it sound like “the tubes are clogged,” which is ridiculous (unless you are on at&t).
No. They are transmitted on separate virtual pipes, not separate physical pipes. Those dishes you see on cell towers have physical limits, and that's the only real pipe. Voice calls and Freeping are each taking a slice of that real pie.
Interesting story: One of the physical limits that exists is power, and you can increase the size of the "real" pipe by turning up the juice (but only to a point). There was a security guard who regularly set up a lawn chair adjecent to one of he large dishes on the ground. The microwave transmissions would warm him in the Canadian Winter. Well, he did it on Christmas day like he'd always done, but he didn't know they had cranked up the power to accommodate the anticipated Christmas phone traffic. You can guess how that one ended.