I don't get what you're saying.

Interviewed cop says they'll go after them if they don't cooperate, which would mean a) requesting assistance to law enforcement via means such as backdoors and server seizures and b) resulting in legal steps against the organization and its members by France. Who in their right mind wouldn't take this a threat? After Wikileaks, the Telegram CEO, pushes for chat control and other authoritarian techniques?

Sure, the cop might be a nobody in the grand scheme of things but they're representing a government agency publicly so they're probably not babbling out nonsense in a bar somewhere, being overheard by a reporter.