No, Russia is tough on oligarchs that split from Putin. There is no non-corrupt oligarch.

Yes and that's also exactly how Xi deals with illoyal people in China - just accuse them of "corruption". It's the authoritarian playbook.

I think they are meaning "the measure seems meaningless as it would imply Russia is even tougher on corruption" rather than "Russian leadership cares deeply about corruption".

It's a risky play to try to communicate over the internet to a bunch of us literalist nerds :p.