The issue with that is that depending on their age they might just not even know! Trauma it's also a big memory eraser. I say this as a latinamerican, in my country under dictatorship children were stolen from their mothers in captivity and then sold to rich folk or military families. Most don't even know. It's also a complex issue, if those children are then rehomed, whether we like it or not, they'll be raised by someone else, bad or good guardian, they'll soak up the culture, the hate for Russia or the propaganda of it depending on the caretaker. It's incredibly fickle.

And I don't believe the russian institutions behind these would be careful enough to place them all in highly "trusted" homes either so.

What will probably happen in the end it's that you'll end up with a bunch of, knowingly or not, unwilling diaspora kids with a similar but not close enough culture.