Will Updating macOS delete Bootcamp Windows?
Solution 1:
Updating macOS should not impact data on any other partitions on your disk.
Nevertheless it's always a good idea to ensure you have a backup of everything important before performing major maintenance activities (as e.g. an OS upgrade).
Solution 2:
It will not delete your Bootcamp partition unless you do a clean install and delete your bootcamp partition from Recovery Mode (partition).