The ban on Dorje Shugden has caused immeasurable mental and physical damage to many especially to the Tibetans in exile. It is impossible to reverse the damage which had occurred since the outset of the ban. How do you compensate for all the emotional pain, agony, anguish, suffering, anger, disappointment, fear, panic, worry, etc that had arisen? How do you compensate for all the financial loss? How do you compensate for the loss of lives?
In the conventional sense, His Holiness Dalai Lama appears to be wrong about the ban! However, how could HHDL be wrong if He is an emanation of Chenrezig who is fully enlightened, omniscient and compassionate? From the perspective of a pure view, HHDL seems to have a higher purpose in imposing the ban. It could be for the overall wellbeing of the Dorje Shugden Lineage and followers. Currently we don't have the wisdom to know why HHDL had initiated the ban and fully understood HHDL's intention.
It is not the case with Central Tibetan Administration (CTA) and those who had ignorantly supported the ban! They will unfortunately bear the consequences of their negative actions!
It will take a while after the ban is lifted before Shugden followers can totally forget about their sufferings over the last 30 years.