Inadvertently, probably, you just made a rationalization for replacing and updating modernizing monuments and historic names that are attached to buildings.
"Migration is the key determinant in history."
Well, the migration continues.
A Guardian headline "Human migration will be a defining issue of this century. How best to cope?"
It is fuelled by two drivers 1) failed states that have created 65 million displaced persons in the world 2) greater mobility than ever before in history.
Canada can't build a wall.
It really comes down to a numbers game.
White European males like Macdonald, Langevin, Cornwallis, Robert E. Lee,  Stonewall Jackson etc etc  represent a white European hierarchy from the past that is fading.
As new immigrants and refugees change the colour and cultural texture of Canada and the U.S.,  it is natural they will create new myths and symbols.
This historian's appreciation of all things past, will be trampled over by new figures of veneration.
The migration continues.