Firstly, it's common for PS's to suggest chin implants when a patient tells them they are dissatisfied with their chin. It's uncommon for them to open topic of the possibility of your whole lower jaw being recessed because if it's that or that too, it's not in their venue to address all of that... if it is that.
Secondly, there's something that seems uncommon to me about this maxfax you went to. I'm assuming you have not left information out about this visit and it was the maxfax who didn't open topic about the possibility of your whole lower jaw being recessed (in addition to chin). Such a possibility, to rule in or rule out, is explored via an X-ray CEPH and if he doesn't have the device to take one, he should refer you to a place where you can have one taken. Basically, it's something that the maxfax needs to look at in the process of AT LEAST giving you BASIC info as to whether or not your chin is the ONLY factor in the recession you're seeing. Another concern is his 'jobbing out' the surgery plan, which by the way, a CEPH, same type of X ray photo this maxfax won't take himself to even look at the jaw to jaw and bite relationship, would be needed to plan the genio.
Seek out ANOTHER maxfax who would not leave you in the lurch as to the POSSIBILITY of your chin recession also being coupled with jaw recession.