So they might end up taking a biased decision against Bitcoin.
Might? They will. It however doesn't mean that it will result in a ban or whatever. It can also just be a public statement that they don't recommend investing in Bitcoin, or to even use it due to the volatility or whatever other reasons.
I am however more inclined to think that everything they come up with hasn't exactly to do with the volatility or unregulated nature of Bitcoin, but more with the fact that they don't want capital to leave their country.
Either way, it doesn't necessarily have to be in Bitcoin's favor, which it likely never will be, and that isn't just related to Iran, but basically any other country ~ we can only hope for reasonable regulations.