That's fair critique. Their website uses third parties to work and some of the services they shouldn't use. Others they probably have to use.
But you are implying that this makes the app itself broken. I don't think this is proof that the app itself is not respecting privacy like their legal documents say.
I won't fight for them. I've never even been on their website. But this is classic situation where someone else is in charge of website and marketing. I wouldn't be surprised if slapping google analytics on a website was standard for every other "privacy focused" marketing product.
When someone takes clients' private information and shares it with other businesses without providing transparency over this fact, it is actually a breach of privacy. In terms of Signal, these breaches are both about their application and about their website, illustrating a complex issue with privacy in their business organization.
I'm not saying that the app is broken, I said that it handles user privacy unacceptably poorly.
You can visit their donation page [1] that contains ad pixels from LinkedIn, Google Tag Manager and Reddit. Again, no details in the privacy terms [2] about sharing visitor data to those companies.
[1] https://signal.org/donate/
[2] https://support.signal.org/hc/en-us/articles/360032293251-Do...