I read something yesterday about the Russian military uses Telegram almost exclusively, and Russia says the French arrested him to get the decryption keys.
What decryption keys even, group chats cannot be encrypted and private chats are unencrypted by default and even encrypted chats shouldn't have the encryption key stored on any servers unless there is a backdoor.
Oh you mean server-side encryption? I'm fairly certain that Telegram is already handing out these keys anyway, since every country has laws regarding that. Server-side encryption is worth jack shit