PhilipG,
Nothing to do with software
AFAIK. My understanding is that the jets aren't coming due to Program priorities and effort at this particular time of this particular year. The right call in the circumstances. That news probably upsets the minority of UK tax payers who go to airshows but that's life. Oh, and the jets aren't the developmental ones; they are line aircraft running fully released software (vice test sw).
The reason SSL hasn't been tried is a function of an incomplete QE-Class carrier to complete it on. Those tests happen in 2018 or so, by which time Block 3F sw will hopefully be on the street.