This ruling is in line with Comm v. Hyde. There is NOTHING new about this ruling, at least regards the recording issue. There is nothing wrong with OPENLY recording cops in MA or anyone else who are speaking in normal voice in public. By being in public, they are forfeiting their privacy. This is inline with 4th Amendment thinking.
In technical terms, the above is 3rd party recording that is not considered 3rd party eavesdropping because there is no REP (reasonable expectation of privacy).
Now, what this ruling DOES bring as new is the cops who think that they have veto power over your OPEN recording of them are now on notice, in federal court you have zero shelter from the liability of arresting someone because you don't like that they are recording you in public. This is new. The cops are not being granted qualified immunity and are on the hook for the damages of denying Glik his rights by improperly arresting him. That is a step in the right direction.
The problem here is if you are recording your interaction with a cop, what does that cop have to do to stop your recording? "Detain" you, that is what. Once they do, for their "safety" of course, they now control your recording equipment and can turn it off. Nothing in the above ruling changes this. They can do this, beat you to a pulp, or just ignore you to illustrate both extremes, and there will be no record of it.
What has not changed is Comm v. Hyde which makes 2nd party recording a privacy issue. This is not the case in 38 other states but here in MA, people are presumed to have a REP right from secret recording even when the recorders are privy to what is being said. That is absurd if you dissect it, but that is where Hyde dropped us. So for an example, if party A has a conversation with B, A can't record it because B supposedly has a REP privacy right yet A has heard everything B said. They were having a conversation for christ's sake. B gave up their privacy to the statements once they engaged in said conversation. So A can detail the conversation to whomever will listen but if B denies what was said or that the conversation even took place, it becomes a he said, she said situation. Now, who does this protect? It protects B. It protects liars, cheats and thieves. Because it allows them to lie about what took place. There is a line in Hyde where the SJC basically acknowledges this by stating to allow surreptitious recording of cops will allow the citizens to monitor and find corruption.