That's not true at all. Media coverage of law enforcement matters is filled with quotes, anonymous and named, from the police community. That's not less true right now.
There's nothing stopping these people from talking to the press. Like anyone with an opinion, they're happy to do it for the most part.
It's true that police officers and their families do have 1st Amendment protections, but they are also governed by employment law and can be castigated by brass, fellow officers if they cause ripples which screw up a case or department morale.
> There's nothing stopping these people from talking to the press.
If you work for a company, were told that only the communications office was allowed to talk to the press about company business, the press asked you for a quote about something your company did, and you undermined the company's product/feature/initiative in a named quote, do you think your employer has the legal right to fire you for insubordination?
If it's police wives, they probably aren't allowed to have the information by department policy, so the officer who passed on that information could (and should) receive a reprimand.
With legal cases, police officers can't just go talking to press about a case because it could be used by the defense attorney to muddy the facts of the investigation or get some evidence thrown out.