The ACLU is not the same organization that it used to be. That neo nazi march they defended was almost 50 years ago. It is doubtful they would take a similar stance today.
Not anymore. The Charlottesville incident was the straw that broke the camel's back [0][1][2].
There was a revolt from donors and plenty of lawyers against their stance during Charlottesville.
[0] - https://www.nytimes.com/2021/06/06/us/aclu-free-speech.html
[1] - https://www.nytimes.com/2017/08/17/opinion/aclu-first-amendm...
[2] - https://www.nytimes.com/2019/10/04/opinion/sunday/free-speec...
But that's the rub, PEACEABLY. Clearly what happened in Charlottesville violated that and is no longer protected under the constitution. But we can't ever truly predict the actions of an individual in a large group.
I'm very torn. I feel like we veer into Minority Report if we start having to predict what assemblies are prone to violation or not.