That was a pretty small fix, not sure why it was even mentioned, it just fixed a bug when setting the IMU to a different heading using the VEXcode inertial::setHeading method, float values were being truncated to the closest integer value. It did not affect reading heading from the IMU.
VEX does not publish detailed release notes.
Major changes for V1.1.0 were support for GPS sensor, some internal changes to the controller in preparation for proposed changes to competition control and support for some hardware updates caused by the global semi-conductor shortage.