Does anyone know if iOS in lockdown mode stops syncing mail, imessage, call history etc to your other apple devices? I am wondering if reporter's stuff was all synced to the non lockdown MacBook from the iPhone
https://support.apple.com/en-us/105120
Looks like lockdown mode is focused on blocking inbound threats, not the sharing of data from the device.
I can't imagine it would. The accounts don't flow through the phone you're just logged in to them on both devices.
They usually ask you to enable lockdown mode on all your devices for advanced protection, even though you can skip it if you want.