Yes it will. It's idiotic to think that it won't. If Iran allowed to Saudis to fund schools, if Iran allowed sunni Imamas to say whatever they wanted and if Iran allowed its sunni citizens to follow Saudi wahabism, we'd have the same problems. But we don't.
You're arguing against logic.
In 60's, Pakistan economic was quite progressive, stable as nation, many sects of Islam lived side by side peacefully in Pakistan. Again, those sects not the problems considering the followers of those sects are people like us, you and anyone in the whole world.
The problem is the intention of certain nations. It is all about power, influence, control. There is long story behind why Dubai is progressive city and Karachi is not. There is long story between Iran and Pakistan on Balochistan [largest province of Pakistan] that posses goldmine resources, hence Chinese invested project, Gawadar project.
In today's game, if you don't want certain nations to progress, the policy of sectarian violence is the way to do so. Iran and Saudi Arabia are famous for that. There is the reason why ME is in mess now, not before. There is the reason Pakistan situation is in turmoil now, not in 60's.
Those nations [Iran+Arabia]that is responsible for the mess in ME is now enjoying thriving positions in the world. That is ugly truth that most Arabians and Iranians avoid that all the times, and play blame-game with each other to escape from the reality. Eventually, their fostered policy, sectarian violence, will backfire on the very same nations that started on ME and MW [Muslim World].
As long as Pakistan remains neutral and doesn't associate any sects of Islam with crime, and treat terrorism as terrorism, then Pakistan will be fine. Zarb-e-Azb attests to that as the unity from every sects of Islam including minority in Pakistan is supporting Pakistani army against TTP and treating TTP as terrorist group alone not associating with any sects of Islam for the sake of peace and unity.