I think you're overestimating how sensitive immigrants are to this stuff. Comarriage is way more about preserving their family culture than it is about finding someone accepting. Religion and spoken-at-home language will matter.
Sizeable chunks of some immigrant populations simply won't melt, which IMO is fine in a place like Canada or the US. They'll still work with everyone else, and I feel like profession and class are both way bigger dividers than ethnicity anyway. A white SWE probably knows more Indian SWEs than white janitors.
Religion is somewhat a concern, but it's completely dwarfed by issues around the religiosity of non-immigrant populations.
Speaking a different language at home is a really good thing. Kids are going to pick up English through immersion anyway, so they're going to turn out bi/multilingual. That's great.
So, most of my extended family is from the Middle East, mostly Christian with some Muslim in-laws. My understanding is that those immigrant groups are far more religious and traditional than the average non-immigrant (though less than the extreme parts), which of course I'm fine with cause they're my own. But I'm not sure what you're expecting from them.
I'm not expecting anything from them! Just pointing out that the actual problem with religion in, say, the US, is white Christian nationalism, with fundamentalist Islam a distant second.
(By the way, I do think immigrants integrating into society is a moral good! I'm very left-wing and it's one of my most conservative beliefs. But the burden of that should be on the hegemonic/native-born population, not on immigrant communities.)
Sizeable chunks of some immigrant populations simply won't melt, which IMO is fine in a place like Canada or the US. They'll still work with everyone else, and I feel like profession and class are both way bigger dividers than ethnicity anyway. A white SWE probably knows more Indian SWEs than white janitors.