It is never a good practice to try to pull though any raceway with energized conductors. In addition at the equipment ends, the workers would likely be exposed to energized parts. It is unlikely this would be "justified" energized work under the rules in OSHA and NFPA 70E, but not sure about Canada.
I would NEVER try to make a contractor do any work that they see as a safety issue.
If I was the contractor and the owner/engineer tried to force my people to do work that I see as a safety issue, you would have to find another contractor to do the work.