Extremely competent, saying Signal is not private by design.

While very disingenuous, it's not technically incorrect.

Signal is secure by design, and is extremely good at that with a very well designed and vetted cryptographic protocol.

But privacy isn't one of their primary goals, nor should it if it comes at the cost of security; for example, for the longest time you needed to share your phone number with everyone you wanted to talk to, and everyone in every group chat you are a part of could see it.