Because Signal definitely will comply with a judge if given good reasons, like "here is a criminal organization using your app, help us dismantle it" and Telegram is the same as Signal with the exception is Russian.
Also encryption is as good as its weakest link, in this case are humans. Probably police flipped some criminals to be informers and now it's running a smoke&mirrors campaign in media in order to send rest of criminals to make more mistakes.
As for the ideal way to do organized crime the main ingredient is to own judges + police and you're set for life. From time to time let some minor transport get intercepted by your corrupt policemen, have some small fish get fried by your judge and stir waters for a few days in media in their favor. Maybe this news is exactly that and while the newspapers are reporting few millions captured you haul the rest of billions without a hiccup.
