Yeah, tell me when the US will lift Iran restrictions on their hardware first. As for Pakistan, they have the F-16 which depended on US after sales support which could be in jeopardy if the US detected any smuggling of weapons towards undesired groups. Am sure the wise men in charge would not want such to happen.
See, this is where you're wrong, just because China produces copies or lookalikes of the Blackhawks, doesn't mean that you could just do plug and play with the said components.
If you're really insisting on the Taliban be able to maintain their air force ghanima, well let me tell you this.
YES THEY CAN.
The US had expressed it's willingness to engage the Taliban, on condition that they changed and respects human rights (based on Western standards). That means if Kabul wants steady supply of US goods including spare parts, they have to reform in line with the liking of the West, that means embracing democracy, women in politics, maybe LGBT rights, dump the sharia etc.
Which if they accepted, good for them , they've just transform themselves into the exact same government they tried to topple since 20 years ago.