Can't say I had noticed. My AWC was issued when I renewed my SGC. The FEO asked if I had airguns, told me I didn't need to fill in the form and added £5 to the fee.
Everyone that I know who applied for an AWC before their airgiuns became illegal got it issued in time.
I don't agree with airgun licensing, but in the cases of me and the people I know it hasn't made any real difference.