Predictive Programming.
Get the sheeple used to the idea before implementing it.
Also.
Political Commentary.
1984 was written in 1948. The plot takes place in the future but describes the current (1948) political reality.
Put these two together and you get the perfect propaganda mechanism for extensive population thought control.
You put these ideas into peoples heads in such a way as to make them believe that all this is really only possible in the future but can be avoided if people do the right thing now.
Most people are basically good so they get complacent thinking that everyone is probably just like them, good. This leads to most people saying to themselves that someone will take care of things.
Nobody does.
The current situation, what people believe is only in the future, gets revealed slowly, in small increments.
By the time the sheeple wake up, if at all, it's too late.