If it had slipped ISIL's attention that there are no Typhoons in Akrotiri, and they had missed all the news coverage of the repeated extensions of the third Tornado squadron (why bother if Typhoon was ready?), then I'm sure they will have missed the NAO's Major Projects Report, which lays out in excruciating detail the cost and timeline of the aforementioned upgrades (pssst... including something to do with a radar... but that must actually be sensitive because it's redacted).
See page 162 onwards
Blanket stonewalling on security grounds has long since been consigned to history. Any infinitesimal value that the enemy may gain from aggregation of unclassified information must be weighed against the cost to our own side of ill-informed internal debate resulting from an information vacuum. It is important to keep our own people on-message!