Svechnikov, Mintyukov, Suniev, Gridin, Yegorov, Kuznetsov (Yan), Chaly, Provorov, Levshunov...
I could have given you plenty of cases but you will always find an argumentative bias by saying that one played in BCHL, the other in OHL, the other is Belarusian, etc...
My basic idea is that Ryabkin did not sign a KHL contract and can leave Russia. Russian players have already left. Gridin did it at 16. The Russian federation has always been concerned about the departure of Russian players to North America.Neither you nor I know Ryabkin's thoughts. But seeing him leave Russia to play 1 year in the USHL then play in the NCAA is a possible scenario.
And whatever happens I will stick to my idea that USHL is superior to MHL. Besides, if I posted a poll on the site, people would say that there is no debate possible.
A few years ago Russia's National U18 Team competed in the MHL. They tied for 5th. The NTDP has placed anywhere from high to low in the USHL; yet they frequently use U17 players. The proper U18 NTDP is regularly defeating NCAA schools in exhibitions.
The U18 NTDP and Russia's U18 are not on different levels. Games between the two at the U18 worlds have been amazing. This should give you a solid comparison between the leagues.