First, you are incorrect. PII is most definitely protected data in California and California is constantly adding more and more privacy laws. Hence, the DOJ directives in order to comply with California law.And this is where the blender starts to cloud. PHI is Federally protected health datum. PII is not "protected" when it becomes an element of an interaction with Police or certain public services, it becomes public information(except certain witness/victim identifiers). There is no "right" or assumption of privacy when in public. When an interaction between a citizen and a public service occurs that information is now in the public realm, with any protected health information redacted.
And this is when people start to smash the two together and they really shouldn't. They are two literally different things with two totally different law sets protecting/administering them. And as I had stated...this is the point in time SOME department/agencies are "taking advantage of" the moment/confusion to use PII as an excuse to use encryption. It is not, bills are not laws. MOU's from the AG's office/DOJ aren't laws they are current political interpretations.
And as far as "officer safety" lol - what did they do for the last 5k+ years...without encryption....exactly.
Rights are like muscles, you don't exercise them, you'll lose them.
Second, and to respond to your exact quote, encryption has been around for 3,000+ years going back to the Egyptians to keep information out of the hands of the enemy. Radio, which has been around for ~115 years, has also had encryption for the same reason. As far as law enforcement scanning is concerned, up until 15 to 20 years ago, the bad guy had to own a scanner, keep it with them or listen to it regularly and know how to program and use one. Now, you just have to have a smart phone or Internet connection. The advent of streaming law enforcement radio over the Internet took the bad guy count from a small handful in a jurisdiction to practically everyone.