There was actually a big thing on the old forums since players didn't like the option and wanted it removed.
Afterwards it became more restrictive just to appease those players but it is still around. So it's understandable that some find it strange that players are still asking if it's a thing.
Players wanted it removed back then because a certain someone was exploiting the restoration system pretty harshly and players didn't deem it fair at all. Can't blame them.
One time restore for the entire account.
So lets say you got a weapon back in the past, for whatever reason glitch/misunderstanding/misclick. Then you won't be able to get any other weapons from them, even on a different character.
Also they will only restore an item that has been permaboomed.
Only weapons that were destoryed after the merge or even before?