Under international law, genocide requires the specific intent to destroy a national, ethnic, racial, or religious group.

Yes, and stealing their children and forcing them into your culture fits that description as it has several times in human history, including with Residential Schools in North America.

It’s cultural eradication.

I’m honestly not sure if I would call the overarching conflict a genocide, but Russia is absolutely doing genocidal things with the intent of eradicating Ukrainian culture from the contested regions.