You have put me on the spot and once again I am going to be slated.
If the audiograms were normal, then we can rule out an acoustic neuroma.
If you had caloric tests and an ENG (electronystagmography) and that was normal, then one can rule out an inner ear problem.
Brain tumours rarely present as dizziness and hence this is unlikely.
I think that the ENT surgeon is dotting the "i" and crossing the "t"s.
An MRI would be the logical next step for "leaving no stones unturned"
In my opinion the MRI will be normal.
That is my opinion and the decision is yours.