Sadly, zero repercussions. Who will sue them? Individuals cannot, the process of law is long and requires substantial money. Government is difficult enough to get involved, and will soon lack resources to intervene or impose fines.
I'm not sure if that's the right take: the Americans with Disabilities Act is maybe the most plaintiff-friendly tort law in the US. There's whole law firms specializing in finding viable plaintiffs to take on contingency (i.e at no cost).
Amazon is big enough that they might even be able to get a class action lawsuit going, to be honest. If enough people started coming forward about disability discrimination.
It seems to me that the payout for the employee would need to be enough that they never have to work again because of the risk that they won't be able to find a new jobs after having a lawsuit on their record.
It would be an interesting idea if employees at tech companies organized unions _for each other_. Like the guys at Apple ran the union for Microsoft and negotiated for them and visa versa.
Employees have and will continue to take Amazon to court over issues like this and go completely under the radar. The case would also highly likely be settled out of court to avoid this exact issue because they don't want it in the papers either. For an individual doing a (for Amazon) low stakes lawsuit you're highly sensationalizing the situation.