Any guesses on the likelihood the occupancy date holds anywhere close to December 2020 for lower floors? That's the revised date my friend got in March 2020, seems fairly unlikely to me?
The lower floors are already enclosed and fit-out is probably happening inside. The critical path items are going to be elevators, HVAC systems, fire systems, garage access. It is possible that this happens by December 2020. I have heard that sites continuing work despite COVID are moving slower than usual due to social distancing, some materials issues, some absenteeism, etc.
I don't think it is obvious either way whether your friend's interim occupancy happens in December. I think it could go either way.