It is actually used since long time ago.
Add photos
select the coordinate system of your IMU data (likely Geographic WGS83) import a file with photoname.jpg, lat,lon, elev (I'm not sure if yaw, pich and roll are also considered)
goto align step and choose "ground control" as method for preselecting pairs
this actually helps PS to skip photo pairs that are unlikely to overlap, but this is not a new feature.
In further processes, like orientation refinement, camera coordinates may also be used. In the ground control pane, you can see the photos with their coordinates that can be checked for the absolute orientation if you consider them good enough to participate in the external orientation. See that in the settings dialog you can fix the camera accuracy which is set to 10m by default, so even if checked, camera positions are usually low weighted in the bundle adjustment calculations.
I guess no new role for the IMU in this version