Perhaps I have misunderstood the later Theravada position, I was thinking
of this passage:
From: What the Buddha taught, by Walpola Rahula - online version - Link: http://www.quangduc.com/English/basic/6 ... ht-04.html
"Some popular inaccurately phrased expressions like ‘The Buddha entered into Nirvāna or Parinirvāna after his death’ have given rise to many imaginary speculations about Nirvāna. The moment you hear the phrase that ‘the Buddha entered into Nirvāna or Parinirvāna’, you take Nirvāna to be a state, or a realm, or a position in which there is some sort of existence, and try to imagine it in terms of the senses of the word ‘existence’ as it is known to you. This popular expression ‘entered into Nirvāna’ has no equivalent in the original texts. There is no such thing as ‘entering into Nirvāna after death’. There is a word parinibbuto used to denote the death of the Buddha or an Arahant who has realized Nirvāna, but it does not mean ‘entering into Nirvāna’. Parinibbuto simply mean ‘fully blown out’ or ‘fully extinct’, because the Buddha or an Arahant has no re-existence after his death."