Then this is false advertising and a class-action lawsuit that should have already happened.
This Arstechnica article seems to confirm that they can’t decrypt without user intervention and that they have only ever supplied metadata to law enforcement. I’m no fan of Meta but do you have sources that they have in fact decrypted actual message content at the request of law enforcement?
The Fn and Carl keys can be switched in software. I have a work-issued Lenovo with a similar layout. They can be soft-swapped in the BIOS. There’s also a desktop utility to do the same but I don’t know if they have a Linux version of it. I totally agree, the physical layout is annoying but it has a simple fix.