If the mere use of Signal is banned, traffic analysis tools an DPI can be used to identify users and bring them the unwelcome attention of the regime’s well-staffed secret police. I’m sure the Chinese are selling them surveillance tech, and if not Iranians are quite capable of developing it themselves.
It’s not a simple issue to resolve. WireGuard is better in that it only establishes a flow if authenticated, but UDP traffic is a giveaway.
The bug reporters reacted immaturely to being asked to submit the report on the Signal forum instead of GitHub, but Signal hiding before a CoC to avoid discussing substantive issues is not a good look.