Sorry, but halting enrollment and asking for additional cmc information is not just "part of the change request process". In the end it could be nothing, but this was certainly not expected.
If the FDA sits on the issue for 3 to 6 months then we all know where it is going.( one can blame the FDA for the delay but it does not matter). Remember EU application/approval process and the aftermath and how ADXS announced the withdrawal of the application?