There’s no way they can know that for sure. A change of this magnitude cannot go from experiment to success in such a short time frame. Even if all the code were 100% correct, you can’t call it a success until it’s battle tested in real world scenarios for a while, and that is impossible without time. Same way you can’t cook properly by throwing food into a vulcano. It’s not just about the temperature.
Either the “experiment” claim was a lie or they are being irresponsible.
What if another (unstated) goal of your rewrite was to provide marketing material for how advanced your acquirers AI tools are? The faster the turnaround, the better they (and therefore you) look.