LTE is currently only being used for data, however VoLTE (Voice over LTE) is coming.
It's probably going to be a while. FirstNet still can't seem to get their act together, never mind make any solid decisions. While I'm sure an LTE based network for public safety will have it's place in large population centers, there are still a lot of agencies still using analog. So many have spent millions on P25, it's going to be a while before they can afford to replace those systems.
While that's true, these modern protocols are being designed to keep eavesdropping out. Trunking and other such stuff still has as a base the same general design of radiocommunication that Marconi used.