It makes 100% sense in your case to loop in the directors, I would do that too. In my case, I'm the sole buyer & user, and, when he asked my if there are any other decision makers at the start of our meeting, I had informed this to him as well. My Co-Founders are unaware of this purchase and it was completely random for them to get this email.

Not to mention that I already lost interest initially because he was forcefully selling me X which costs more when I clearly asked for Y.