If you had a medical condition that would affect your work performance, it would need to be made known to your direct supervisor. It sounds like they more than accomodated her limitations so that she could work to the best of her ability.
I'm not curious how her manager found out about her condition, but more how did her NEW manager NOT find out? I can only assume that the way WE are finding out was because the suit was filed and that makes it public information. If that's not the case, then there is a major HIPPA violation going on here.
I suspect that the new manager just didn't think the accomodations were working out. Even if you suffer from all the above problems you shouldn't still be in a training mode after two years. The fact is that she probably was just not earning what they were paying her. IOW even with the accomodations, she still could not perform the essential functions of the job.
No good deed goes unpunished. Here Starbucks accomodated her to bring her on and when the accomodations didn't work out, they discovered that for all their good will all they did was buy a lawsuit.