Hi,
Thanks for your post. I completely understand your situation. I often have clients who receive promotions or make job changes or otherwise have a significant improvement to their employment situation after applying to school. While you can and should email the new information to the adcom as soon as possible, you must understand that it likely will not be considered especially this far along in the process. To be fair to all, adcoms really should only evaluate a candidate based on the material provided at the time of the application. Allowing additional information down the road opens the floodgates - meaning candidates might submit new GMAT scores or recommendations or resumes. It would be difficult for an adcom to draw the line at what is acceptable post application and what is not as well as deadlines on additional information, thus the one firm deadline. However, as I stated above, it doesn't hurt to tell them, but please recognize that it may not be added to your file.
Best,
Stacey