This would make sense since the name is almost 'manure'. They have increased their USA presence by buying John Hancock, but don't know how it would play out in Canada to use the name of a USA patriot. On the other hand this is much higher profile name. Given the choice between the two, I would vote for John Hancock. Even better might be a name that included two patriots, one from each side of the border.
"Even better might be a name that included two patriots, one from each side of the border."
You're kidding right? A company brand as you have astutely pointed out is quite valuable. It makes sense to go with whatever brand is the most recognizable and valued. The value is based on a tradition of excellence in insurance, advertisement and performance.
Sure many US companies use names of heroic people with a reputation they would like to emulate or associate with their product, but they are not limited to US placenames and include other heroes most people may not associate with American heroes. Consider these:
Amazon.com Starbucks -- name of the first mate of the Pequod (Moby Dick) Lil Caesar's Ben Franklin Stoves, Bowie knives and Lincoln logs
The point is don't get too hung up on political correctness. MFC is a multi-national company and MFC seemed to sense that from the time when it used to be called the North American Life Assurance Company.