Biggus,
Your post #2 is quite right. We spend money on planned incremental upgrades not knowing a fleet is to be scrapped and then it is (scrapped).
Bummer.
Do you think there might be more of an issue in knowing that the fleet that isn't going to be scrapped needs to have over a billion spent on it but not mentioning it until after the SDSR?
That may have played some part in how the final decision was made.