I don't think that was why - the special committee report recommended a referendum and switching to Proportional Representation.
Two parties stand to lose the most from that - Liberal and Conservative. NDP, Green, and fringe parties like PPC stand to gain the most, as do the people of Canada, IMO. Trudeau didn't want it to go to a referendum, because the liberals would lose significant power, and likely never again become a majority party, as there is a not-insignificant portion of people who vote Liberal as an anything-but-conservative approach.
Let me know if there's more nuance I missed! It's been a while since I looked into it.