Say that I have a system with a SATA drive, and it's running XP, and the
drive was formatted as NTFS, and in the BIOS I have my SATA drive being
controlled by the on-board SATA controller.

Hypothetically, if in the bios I changed the configuration such that my
SATA drive was being emulated as an IDE drive, would you expect that the
drive would no longer boot into XP?

Or perhaps it would - but only into safe mode?