I seem to recall that the basis for canceling the E-7 program, which was stated by those favoring cancelation, was that space systems will provide (or already are providing) the capability. Plus, airborne platforms have become too vulnerable, they also said.
The cancellation of the E-7 was supposed to be accompanied with the purchase of up another 90 x E-2Ds on the basis that a handful of E-7s would be to vulnerable to deploy in a high risk scenario, whilst you could risk a few E-2Ds.
I noted previously that they deployed at least 5 x E-2Ds into theatre nearly 2 weeks ago.
Iran