I don’t really like Apple, but once in a while they do the right thing. This comes from the App store’s new labels on apps.
Signal just has “Contact info” under the “Data NOT linked to you” category. This is just the phone number + contact discovery.
UPDATE
There’s another post adding telegram here. This is what it looks like:
That explains a lot of things. I don’t receive notifications in apps I rarely use, but What’sApp always worked (while other widespread apps didn’t like Discord or Slack). The fact that it’s in an allow-list for this kind of stuff explains it. Fuck What’sApp!