Sorry, that's not what I was trying to convey here. "Free speech as a dog whistle" is people using the term free speech but not actually meaning it. More of a "free speech for me, but not for thee," but the second part isn't explicitly said. I do mean dog whistle, which is
covert speech. But speech can only be covert (undertone) if there is a non-covert overtone (otherwise it wouldn't be hidden). So why I'm criticizing here is because the CEO said that Twitter is a place of cancel culture, which comes a lot from users, but said that that can't happen on Parler and then just targeted extremist right wing groups to adopt the platform. He flies under the flag of free speech but the intent was to create a network where right wing extremists could talk within a bubble. There's nothing wrong with that (except for the extremist part) but that isn't exactly free speech focused, that's a niche focus. There's a big difference if you develop a product and it is adopted by a certain group verses if you specifically target that group, use their language, go on their platforms, and actively encourage that group to adopt your platform without even making any attempt to get other groups to join. Essentially Parler said Twitter is a left wing echo chamber and wanted to create a right wing echo chamber.
The intent was never to create a free speech platform, the intent was to create a right wing platform. Intent matters.
To clarify on the dog whistling part more, let's think about a recent example. Conservatives have frequently said that free speech is one of the most important things (Fox News, Trump, etc, not your neighbor). But then these groups also advocated for kicking athletes out of the country for kneeling in protest[0]. The president used his position of power to lead a boycott against a private organization[1]. The hypocrisy here is about that there is no right form of protest if you don't agree with me but even extreme forms of protest are okay if you do agree with me. Someone who says that is not actually advocating for free speech no matter how often they use the term. You saw organizations and the president saying that this wasn't a protest and that if it was they should do it another way. Then you see BLM and say that they should have protested peacefully and we would have solved the problems. From a different perspective you can see this as protesting escalating from peaceful to more disruptive and including violence. We see the "two sides" arguments (Charlottesville), encouraging supporters to run Biden's vehicle off the road[2], encouraging kidnapping of a governor[3], and I can go on (do we need to talk about the several cases at the Oregon capital?). Free speech isn't unlimited. Nor is "free speech for me and not for thee" free speech either.
If free speech is unlimited for one group but not for another, that is not free speech it is a dog whistle.
You can call a cat a dog but that doesn't make a cat a dog. And it doesn't matter if you take your cats on walks or you teach it to play fetch or other tricks or convince a bunch of people it is a dog, it is still a cat at the end of the day and won't ever be a dog.
[0] https://www.bbc.com/news/world-us-canada-44232979
[1] https://www.theguardian.com/sport/2017/sep/22/donald-trump-n...
[2] https://www.theguardian.com/us-news/2020/oct/31/biden-harris...
[3] https://www.cnn.com/2020/10/27/politics/trump-gretchen-whitm...