Hi,
EGM96 Global should mean that the z values are geoidal heights (relative to) based on the EGM96 geoid model. That's a very commonly used worldwide geoid model.
When projecting the data, the Z values are unchanged currently, so they'll still be EGM96 geoidal heights.
You'll need to define the input coordinate system. Are you sure that it's WGS84? Surveyed data, if it's been RTK or post-processed is usually on the control network's coordinate system. In Canada, that would be NAD 1983 (CSRS), rather than NAD 1983.
Melita