UN passes resolution to be implemented at that time frame and not as per what happen to region after 7 decade.
The fact remain -
1- There was no Azad Kashmir for UN then. It mandated Indian government to maintain and control state of J&K that include whole Jammu, Kashmir, Laddakh, Askai Chin and GB.
2- The resolution specifically talks about responsibilities for
a) What Pakistan government need to do
b) What India government need to do
c) What UN need to do.
While describing the UN role, it restrict itself in appointing a general secretary as plebiscite administrator. UN is not that incompetent in drafting resolution that it can miss as important aspect as issuing UN forces and its responsibilities when it didn't miss even the possibilities of having locals for maintaining law and order.
It may amuse you but it says in case locals are deemed insufficient by plebiscite administrator, it may ask for more forces from either from India or Pakistan, based on mutually agreed terms.
No UN forces even when there is lack of local help.
Now coming to East Timor and South Sudan
1- Go read the resolutions which should mention the role of UN forces.
2- Those comes under chapter VII of UN charter which is enforceable, means UN has to enforce those resolution, thus comes into picture the UN forces.
@Joe Shearer