The main proceeding just refers to the liquidation of the assets, the majority of which are in Canada. Therefore, it makes sense that the Canadian Courts would take care of the liquidation process.
But the US Court still maintains ultimate jurisdiction under the US Bankruptcy Code since BIOAQ is a Delaware Corporation and Canada has no jurisdiction over the US parent or the common stock. Therefore, the common stock could not be reorganized under CCAA, even if the company was not liquidated.
The stock WILL be cancelled by the US Bankruptcy Court.