No, MS is not common. But think a diagnosis of MS would be an obviously thing to worry about since benzo withdrawl symptoms can mimic MS. MS crossed my mind, as well, during withdrawl. In medicine there is a phrase that goes something like this: when you hear hoofbeats, don't go looking for zebras. This means that when looking for a diagnosis, start with the simplest, most obvious thing(s) first and in our case, benzo withdrawl qualifies as that.
I'm glad you neurologist was able to reassure you. If the symptoms are not worsening significantly and you are functional, than watchful waiting is prudent. I did just have a thought and if you have not had a B12 level checked, then getting that done might be a good idea since B12 deficiency can cause neuropathy.