They did amplify, or I wouldn't have learned about them. Twitter does seem to be trying to keep gender-critical viewpoints secret, but covertly, as they make it really easy to get banned for "hate speech" when you engage in gender-critical speech. The same for other topics that people label as misinformation, such as sharing the actual statistical results from vaccine trials. I never cared about the statistical results until people got banned for sharing them, thus Twitter indirectly amplified.

That is a ridiculously tortured argument. The censor not extending his reach to outside venues doesn't make him any less a censor.

Streisand effect is about information someone is trying to keep hidden. This kind of Twitter moderation fits neither half of that.

I don't want to fuss about what counts as "censorship" or not. That's not productive.

1. Detransition accounts are information 2. Twitter bans users specifically to suppress that information, i.e. minimize its reach, i.e. hide it

Bald-facedly denying censorship is certainly not intellectually productive, might I suggest you simply stop doing that?