I think at a minimum park goers who paid for Genie+ could ask to be reimbursed for it, although as it's not that expensive maybe that's not a huge deal to Disney. But beyond that, I think it could look very bad in court - disabled theme park goers made to pay for their own accommodations. What the legal implications of that are I don't know, but I assume it's the type of scenario Disney would want to avoid.
What many have said is that when FastPass+ was free they could use that as an accommodation without needing an "official" accommodation. That was great so long as it lasted, but now that it's gone, people are reporting that it's created a need for accommodations. I say reporting because I don't claim to know how many of those people genuinely need accommodations and how many are the dreaded TikTok Fakers. It's almost certainly a mix of both. But for at least some percentage of people, the loss of FastPass+ genuinely created a need.