Well, since this thread came up again I did a write-up on Russians in NHL that played in CHL. This post is suffering from low sample sizes but there's not much I can do about it.
There are 33 Russians in NHL, 11 of them played in CHL. I would group them as:
Stars: Kucherov, Radulov
NHL players: Kulikov, Grigorenko, Namestnikov, Tyutin, Zadorov
Fringe NHL players: Burmistrov, Khudobin, Yakupov
Too young to judge: Provorov (but trends as a star).
2-3 stars out of 11 players who made NHL seems not bad but proportion is higher for non-CHL players.
Here's my short review of each player. When I speak about expectations I mean expectations in Russia at the time they left. Scale of talent is [talented<high-profile<future star]. It may carry my own bias since it's hard to check opinions on players at given period because youth hockey isn't a popular topic in Russia.
Burmistrov: moved to the CHL at the age 18 (draft year). He was regarded as a high-profile prospect (had 1 game in the KHL). Spent 1 year in the OHL, got drafted #8. Underachieved.
Grigorenko: moved to the CHL at the age 17 (draft year). He was regarded as a high-profile prospect. Spent 3 years between the QMJHL/AHL/NHL, got drafted #12 (draft day faller). Underachieved - didn't even become #2 C (low chance he does it in the future).
Khudobin: moved to the CHL at the age 19 (draft+2 year). He was regarded as a talanted prospect before that (had 4 games in the RSL the year before). Spent 1 year the WHL being drafted #206. Underachieved, but goalies are notoriously hard to predict.
Kucherov: moved to the CHL at the age 18 (draft+1 year). He was regarded as a future star (had 26 games in the KHL in 2 seasons before). Spent 1 year in the QMJHL being drafted #58. His parents already moved to New York 2 years before his move to the CHL. Fulfilled expectations.
Kulikov: moved to the CHL at the age 18 (draft year). He was regarded as a talented prospect. Spent 1 year in the QMJHL, got drafted #14. Fulfilled expectations - became a #3 D, #2 if you're being generous.
Namestnikov: moved to the CHL at the age 18 (draft year). He was regarded as a talented prospect (played in the VHL the year before). Spent 2 years in the OHL, got drafted #27. Lived in the USA until he was 8 years old. Fulfilled expectations, possibly overachieved.
Provorov: moved to NA at the age 14 (draft year-3). Can't verify but it seems he was regarded as one of the best prospects in Russia in his birth year. Spent 2 years in the WHL, got drafted #7. He has sky-high expectations right now, seems to fulfil them.
Radulov: moved to the CHL at the age 18 (draft year+1). He was regarded as a high-profile prospect (played in RUS-2 the year before + 1 game in the RSL). Spent 2 years in the QMJHL being drafted #15. Fulfilled expectations, possibly overachieved (depending on how you regard his pre-draft projections and/or his career).
Tyutin: moved to the CHL at the age 18 (draft year+1). He was regarded as a high-profile prospect (played in the RSL the year before). Spent 1 year in the OHL being drafted #40. Returned to Russia for a year after the CHL stint. Fulfilled expectations.
Yakupov: moved to the CHL at the age 17 (draft year-1). He was regarded as a talented prospect, got hyped after the move. Spent 2 years in the OHL, got drafted #1. Underachieved.
Zadorov: moved to the CHL at the age 17 (draft year). He was regarded as a high-profile prospect. Spent 2 years between the OHL/NHL, got drafted #16 (draft day faller). Underachieved - right now he is a #3 D but maybe he can still develop.
Some observations: the only player that obviously and significantly got better by playing in the CHL is Provorov - but he moved to NA 2 years before entering it, it was just a step in progression. The poster boy for it could have been Yakupov or maybe Zadorov - but it seems both failed. It's very probable CHL didn't affect careers or development of Khudobin, Kucherov or Tyutin. Moving to the CHL possibly positively affected Kulikov's career and Namestnikov's and Radulov's development; on the other hand, moving to the CHL possibly negatively affected Burmistrov, Grigorenko, Yakupov and Zadorov - both this statements are equally hard to verify. However, at least moving to the CHL around draft year doesn't seem to bring any advantage except in draft position - which may be not an advantage at all either for career or development.
Next wave of Russian CHL alumni - Galiev, Pedan, Valiev, Goldobin, Scherbak, Khokhlachev, Tolchinskiy, Zykov - doesn't look very inspiring.
Some key players to compare in the future:
2013 draft: Nichushkin (#10, KHL/VHL), Zadorov (#16, OHL since draft year), Buchnevich (#75, MHL/KHL, 8 points in 10 games with NYR)
2014 draft: Scherbak (#26, WHL since draft year), Goldobin (#27, OHL since draft year-1, went to Finland), Kamenev (#45, MHL/KHL, in the AHL since 2015), Sorokin (#78, KHL)
2015 draft: Provorov (#7, WHL, moved to NA at 14), Guryanov (#12, MHL/KHL, in the AHL since 2016), E. Svechnikov (#19, QMJHL since draft year), Samsonov (#22, MHL), Zborovsky (#79, WHL since draft year), Kaprizov (#135, KHL)
2016 draft: Sergachev (#9, OHL since draft year), Rubtsov (#22, MHL U-18 team), Abramov (#65, QMJHL since draft year), Sokolov (#196, OHL since draft year, was seen as possible top-5 pick the year before)
2017 draft: Kostin (MHL, supposed top Russian player in the draft), Popugaev (WHL since draft year-1), Minulin (WHL since draft year-1)
2018 draft: A. Svechnikov (USHL, supposed top Russian player in the draft), Khovanov (MHL, former linemate of Svechnikov), Nizhnikov (drafted #7 in OHL draft (not import!))
Some overagers to check on: Mironov, Golyshev, Paigin, Korshkov - didn't include them in drafts because being overaged means they're supposed to be better scouted.
Some other players in future drafts relevant to the topic, but I'm too lazy to expand because they may not amount to much: Kuznetsov (overager), Chekhovich, Lipanov, Samorukov, Poddubnyi, Gogolev, Zhukov, Smirnov (overager).