I just posed this question on sci-fi.stackexchange and had my wording corrected from reveal to revelation.
I realise that to have said that too early in the film would have ruined the big reveal. Is there some in-universe reason for Palpatine to refer to Luke's father as Anakin? Some kind of psychological game that Palpatine is playing with Vader, perhaps?
I thought reveal was the correct word but I wanted to check the difference with experts.