According to my son who used to work there, HBC in Moncton was "marginally" profitable, but that was in a dying mall, and as you say, the situation would likely be better at Champlain Place.
HBC is a multinational now and, although considered a Canadian company, is for all intents and purposes controlled by US investors. A truly Canadian company probably would be interested in reestablishing a presence in NB. I'm not so sure about a multinational conglomerate though.
Maybe I'm just being pessimistic this morning. It's the general gloom I feel over Trudeau's small business tax plan getting me down.......