There are different types of electricians and they are all very capable at what they do. There are commercial construction electricians, maintenance electricians, residential electricians, and high voltage electricians to name a few. None of them know everything and this could be why the AFCI breakers got left out of the deal if you got a non-residential electrician.

I would ask the electrician to install the AFCI devices and if they refuse I would do it myself. Apparently this was not inspected and you most likely you got a deal and the AFCI breakers were not in the price so you can afford to do it yourself if needed.

If it was inspected then you need to stand your ground with the electrician and have them install them.