There are a few threads on this forum related to MY20 protection.
Syn3 Updater for MY20/MY21! - Ford / Sync 3 - CyanLabs Official Community
My20 NA AutoInstall Discussion - Syn3Updater - Ford / Sync 3 - CyanLabs Official Community
Need MY20/MY21 Interrogator Logs! - Ford / Sync 3 - CyanLabs Official Community
Essentially, MY20+ vehicles cannot currently utilize the reformat method as it will brick the module (incompatible display drivers). Therefore, if MY20 protection is enabled, it will guarantee that the reformat method will not be used and keep your unit safe.
The main reason you would want to reformat is to install new maps as that is the “cleanest” way of doing so. However, an AutoInstall (in-place upgrade) is possible and this is what the updater does if you have MY20 protection enabled. There are currently some issues with the AutoInstall method for NA maps so further testing has to be done but there are workarounds to the issues.