Best I can tell you really just want
AssociationThread. It circumvents the
Association and the
p = AssociationThread[Range, Range];
AssociationThread[Keys@p, N@Exp[FoldList[Plus, Values[p]]]]
That does what you were doing before in a few fewer calls. Also note that
Associations support lots of functional programming stuff.
Map exist of course and
KeyValueMap is there too.
If you're wondering why
FoldList doesn't do this natively consider that
FoldList are supposed to be direct counter-parts.
FoldList could return an
Association with the keys realigned, but that wouldn't make sense with
Fold. So there's no way to make an intuitive, compatible definition across both of them. And so best to one for neither of them. With
AssociationThread rebuilding your association is trivial anyway, so I think they didn't really see the need either.