I personally think that because Riot is doing a independent investigation, esic won't have much say on the punishment.
FBI and esic work hand in hand with valve for the investigation and how the punishment will be for csgo, but Riot heavily relies on the csgo community to succeed, probably swaying them to give light punishments
I thought about it again, and I would personally just give warnings, especially since these the people who did it are super young and aren't making a dime off of being semi-pros.
Also, I'm pretty sure the FBIs involvement is more with the betting syndicates, not the players.