The IWM press release states in part "We will be making some exciting changes to our own Air Show programme and look forward to sharing more details in the coming months".
Being suggested on another forum that IWM may be wanting to run an airshow on the FL weekend in their own name, and keep all the gross revenue (20,000 people/day x 2 days x £35/ticket = £1.5M, plus income from car parks, trade stands etc). Seems to make sense to me.