This is the most bizarre think I have seen in politics in ages, well, okay, since Monsef beat up her fellow Liberals with wild accusations regarding their hard work on democratic reform committee all the while proving that she either did not read the report or did not understand it.
First, Boeing is completely within its right to challenge Canada's subsidies to Bombardier and tying this to the Super Hornets seems more Trump-like than Liberal.
Second, even threatening to cancel the purchase of the Super Hornets puts the lie to the Liberal's statement that they can't wait for a competitive process to fill the "gap" in our air defences. 
Third, this has all the hall marks of the Liberals desperately trying to get out of their promise (how many times have we seen that) to buy the Super Hornets after realizing what a truly dumb promise it was (e.g. HE 101) and that the auditor general would tear them apart in a few years for wasting billions of dollars.