Both Iran and Pakistan have deported similar numbers of refugees from Afghanistan in the last few months
Quite the opposite. A rather large number of Afghans who have settled in neighboring countries brought a massive number of issues, mostly drug dealing and armed confrontations with local police. Not to mention that the cheap labor from Afghan refugees dwarfs in comparison to the amount of aid that many require just to get by.
They were tolerated as long as the powers in Afghanistan were not bothersome, but this isn’t the case anymore. Taliban are no longer viewed in friendly terms by either Pakistan or Iran, hence the mass deportations. The policy didn’t really encounter significant push back by locals. Might be worth paying attention to that before thinking this is going to negatively effect Iran