The need to go encrypted is coming from a couple of different directions.
Yeah, ass-hats like these guys are part of it. I'm sure the agency is aware and has ways of dealing with this.
Streaming isn't helping, but it's not the main cause, it just made it easier for others to listen (reference said ass-hattery above).
The FBI has rules regarding the broadcast of CJI/PII in the clear, but it's not been well enforced. That's starting to change. California has adopted the FBI/CaDOJ requirements to keep CJI/PII encrypted, much to the frustration of some hobbyists. The FBI will likely be starting to push this more, as well state justice departments.
I agree with AB5ID, there's really no reversing it a this point, the drivers are there and they are based on sound principals. Banning streaming, adding delays, etc. are not going to stop this as none of them fix the core issue.