Whilst it will be interesting to see the F35 "in the flesh" for the first time (for most), evidence previously posted on this forum suggests that looking at a parked Vulcan may be more exciting than seeing the new wonderjet's display.
There really has to be more to this than is being made public - having sat on both sides of the RIAT fence, and witnessed the juggling act (even in the week of the show) to get things into the display at short notice, mixed civ/mil displays approved etc etc, I cannot believe this is simply a matter of there not being time in the programme for the Vulcan to have a 7 minute slot.