Don't forget the most important thing is people have to hold their coins in non custodial wallet, if they hold in centralized exchange, they might suffer the same. But, they might have a problem when they want to cash out because many exchanges like to freeze or refuse coins from rival countries.
1) The government of Iran is doing it themselves to make the population hate Israel more.
2) Inside job at the bank (and exchange) with a convenient target to blame it on
3) Someone else who did not want the spotlight on them.
I don't think the first and second are make sense because Muslim countries already hate Israel since they were in their moms' belly.
For the third conspiracy, it might be possible.