I very much doubt Gagarin was the source of CFD; the facility in Albuquerque that Fastjack and Riser and the rest of the gang raided seems a much more plausible source.
And I'm confident the Boston situation will play a big role in which Megacorp ends up falling. NeoNET, EVO, and Aztechnology (in that order) all have a stake in that particular kerfuffle as members of Project Vulcan, and if the information about the project were to leak out I'd wager one of those takes the fall.
I'd be personally astonished if S-K, Ares, or Horizon goes down, though the latter certainly has had their public perception changed between the loss in Amazonia and the technomancer massacre. I'd also consider it unlikely that MCT, Renraku, or Shiawase would falter significantly, and Wuxing doesn't seem to have a lot going on in the public eye these days.
Sader-Krupp is likely taking a hit in terms of ranking what with the fallout from the Dragon Civil War and all of the frenemies ganging up on Lofwyr himself. What the top 10 will look like is impossible to say simply because one of the big 10 might not be there anymore. If I had to guess, I'd rank them accordingly:
1: NeoNET
2: Saeder-Krupp
3: Aztechnology
4: Shiawase Corporation
5: Mitsuhama Computer Technologies
6: Renraku Computer Systems
7: Wuxing Incorporated
8: Ares Macrotechnology
9: Horizon
10: Unknown
I'd hedge my bets that EVO goes down simply because NeoNET has the most incentive to blame someone else involved in Project Vulcan, and with the Monad taking over Gagarin it seems like EVO is the corp with the most negative public perception recently. If NeoNET can spin the event in their favour I could see them coming out on top.