>with no indication that even at the third and later generations these preferences are lost

That's likely an unintended side effect of the change in western attitudes on integration, going from "conform" to "melting pot" and now to "cultural stew". The pressure to adapt to the new country's values is less than it used to be while it is also encouraged for cultural communities to form and persist. Beyond that, the revolution in cheap global communications likely as plays a role, as cultural values can be reinforced in the new country from the source country. It may be that the only way to change the attitudes towards gender in the Canadian-Indian community will be to change those attitudes in India itself. That of course gets us into the messy territory of cultural imperialism.

I’ve known a few Indian women who suggested I would be disappointed if I had girls. I never had the courage to ask I if they hated their own existence or something.

Wait, how are they able to do this? Do they selectively abort on sex determination? I suppose sex determination isn't illegal in North America like it is in South Asia.