Greetings,
I’m a college professor, and I have a student that is going to use HoloLens to develop some assistive applications. Is it necessary to buy a Pro license for Unity3D (since we are at a University with a pretty big budget), or does the HoloLens Technical Preview have difference license terms?
HoloLens does not require a Pro Unity license to use as long as the student qualify for the Personal Edition (see Real-time tools for 3D, AR, and VR development | Products). If Unity is being installed in a lab for general use at the Univserity you will want to review this site for information about Educational Licenses: Unity for Educators | Unity Education