Hi and welcome,
From my understanding ON and its association with MS is generally that if you have some brain lesions on your brain MRI as well as being dx with ON you have an increased odds of developing MS at some stage within the next 5 years.....if you dont have any brain lesions your odds of developing MS in that time frame are quite low.
Unfortunately no one can definitively tell you if you will develop MS or not if your MRI's weren't abnormal or more suggestive of a neurological condition like MS, it is possible for lesions to develop for various medical reasons, most lesions are not demyelinating MS lesions though, and ON could still be a stand alone situation.
Honestly the only thing anyone can do under the circumstances would be to get fully assessed by an MS specialising neurologist and proactively do regular 6-12 month neurological assessments and update brain and spinal MRI's.
Sorry i couldn't give you a more black and white answer, there isn't enough diagnostic information to point in any specific direction if all you have so far is Bilateral ON, try to be open minded and not worry too much about a medical condition that you might never be diagnosed with.
Hope that helps a little.........JJ