Hello Stefan,
I think you have already found the C4C field in the mapping.
I am not sure it is displayed in C4C at all.
The idea is, if Sales Area is marked for deletion in ERP, it gets corresponding lifecycle status in C4C (you can find the exact logic in field mapping). Basically Sales Area will not be displayed in C4C at all if it is deactivated in ERP.
Regards,
Maxim