With the Model S and Model X, the Canadian version is slightly different from the United States version. That's because Tesla designed to US standards and then handles foreign versions essentially as an options package. Two of the most obvious differences between the cars in the United States and Canada are that the Canadian version has red seat belt release buttons instead of same-color buttons (black or white), and the Canadian version doesn't let you turn off the daytime running lights. No other car company does this, so Canadian regulations are generally applied to all cars sold in the United States except Teslas. The downside of this is that you can't import a used Tesla from the United States into Canada (it's not on their approved list, even if you tweak everything to get it to comply with their standards). Personally, I really like the solid-color seat belt receptacles; they give the car one more unique feature.
So what does this have to do with the Model 3?
It appears that the ease-of-manufacturing effort includes having a single model that meets all regulations, so there will be no customization for Canada. Europe will still require a different charging port, but otherwise the left-hand-drive cars are likely to be identical around the world.
What evidence points to this?
First, it seems like an obvious choice, given Tesla's statements about simplifying manufacturing. But more recently, there have been photos posted of the Model 3 interior. Sure enough, they have red seat belt release buttons. It's just one little thing, but the implications are clear.