I wish people would stop making this claim without supporting it in any way. It's kind of a ludicrous claim. Signal bears no resemblance to Parler, and there are various other reasons why this analogy is poorly drawn, like the fact that Signal's traffic is entirely private and Apple would no way of knowing the contents of said traffic, and the fact that Signal could not possibly "moderate" said traffic for the same reason.
You make a good point. Though I have to agree with Snowden when he says this will be remembered as a turning point in the battle for control over digital speech.
A good argument could be made we don't need end to end encryption without a back door. And in this environment, there may be little political opposition.
A lot of the speech that's being labeled as "inciting violence" on Parler would feel different if it was spoken privately. The fact that it's being communicated publicly puts it in a different category, almost like you're saying it on TV or in the proverbial town square. I don't think this is setting any sort of precedent for attacking private communications.
I do recall various other chat apps being painted as being used by "terrorists" in the past. For some, the fact that bad people can communicate at all is something they would not like to have, at the expense of good people having access to those tools in some cases.
