Lewis had just gotten that '4 star' 1-2 weeks ago from Rivals.
The way those recruiting sites work, if he signs with Ohio, he'll probably drop back to a 3-star.
In the seven years I have been tracking Ohio recruits, usually 4-6 recruits a year are rated up after verballing to Ohio, and I can't ever document a case of a recruit having their rating lowered. I haven't been tracking it as closely the last couple years, though. I attribute the rating changes to updates related to their Senior year performance, not who they signed with, and since Ohio generally identifies under-rated players, it perhaps isn't surprising that many put in strong Senior years.