There are limitations there though. E.g. if a broad warrant to reconstruct all your messages were issued, Apple would refuse to honor it, if only due to technic

There are limitations there though. E.g. if a broad warrant to reconstruct all your messages were issued, Apple would refuse to honor it, if only due to technical infeasibility. It's one thing to execute a warrant for "data of suspect A" and another thing to execute a warrant for "access the iCloud backups of every single person who has it enabled, decrypt their backed up messages, and return any message that was received from or sent to suspect A". On the other hand the government could certainly find a specific individual they know you've messaged with, and execute a warrant specifically for their conversations with you.