Citizen's United isn't even really about free expression IMO, and I personally don't think people are all that split on it anyways, I think it's just a case where the people and the establishment disagree. BDS I'm simply not familiar with.
It does seem that there are new mounting challenges to free expression right now, but they're relatively new and it's unclear if they will stick around yet.
unfortunately, it is about free expression in the opinion of the supreme court:
'the Court found that laws restricting the political spending of corporations and unions are inconsistent with the Free Speech Clause of the First Amendment to the U.S. Constitution.' [0]
BDS is a topical instance of a bottom-up movement recommending boycotting, divestment and sanctions against organizations that are considered to materially support the israelli government. naturally, you can imagine this attracts strong opinions from many sides. in some cases, states/municipalities have deemed this to be unprotected speech. [1]
[0]: https://en.wikipedia.org/wiki/Citizens_United_v._FEC [1]: https://en.wikipedia.org/wiki/Boycott,_Divestment_and_Sancti...
I think the reason those don't come to mind is because even though they really do regard the interpretation of free speech law, they don't actually feel like they're about expression. When it comes to the Israel/Palestine conflict though, even the opinion that it isn't really about free expression might be controversial, so clearly it is.
wild that of all the examples you could choose to bring up, this is the one. not saying the conversation doesn't need to happen, but i think there are a lot more concrete examples that affect many more people that come to mind first.
for GP, there are a lot of other contested ideas around what constitutes free/protected speech in america that aren't related to pedophilia - much of it revolves around political speech, especially with Citizens United (the supreme court case that effectively declared monetary support for political causes to be considered "free speech"). conversely, ground-up economic speech (such as BDS) is often stifled (even calling for boycotts etc under the BDS framework is not considered protected speech in some places).