Sounds like that could just get them in more trouble?
Such customers are probably on their own - but the article does spell out what they've done, so hints at the solution: VPN to outside Russia in order to sort out moving. (Or stay with Fastmail and accept that you need the VPN to use email, I suppose.) The CEO does often comment on Fastmail submissions here (brongondwana) but I suppose maybe not in this (lawyers involved) case.
Well, I would expect them to address this issue specifically as that is one of the selling points of fastmail. You can get banned on Google for nothing and not being able to reach a person with your data held hostage. Now, this is a comparable situation where data is held hostage unless the customers in Russia have a way to access and retrieve whatever is stored on their accounts.
On top of that there is a question of billing and refunds in the case of long-term plans being paid up front (eg. one year subscription).
Such customers are probably on their own - but the article does spell out what they've done, so hints at the solution: VPN to outside Russia in order to sort out moving. (Or stay with Fastmail and accept that you need the VPN to use email, I suppose.) The CEO does often comment on Fastmail submissions here (brongondwana) but I suppose maybe not in this (lawyers involved) case.