If you do get sued, if you immediately remediate your website, you may be able to get the lawsuit dismissed on mootness (there’s no longer anything in dispute, i.e. plaintiffs are arguing your website is inaccessible but you’ve already made it accessible). This definitely does not mean you should wait to fix your website but it does mean you may have an out.

Every year numerous lawsuits are taken against businesses that fail to follow the ADA’s proposed requirements for web accessibility. This failure occurs because organizations, including state and local government entities, fail to read the ADA Best Practices Tool Kit.8 They also do not follow the most up to date version of the WCAG.9 These two failures are not only detrimental to people with disabilities who want to effectively browse the web, but they are also inexcusable in today’s digitally driven world.
Hey Casey, this is one of the areas where things get a little weird because the W3 doesn’t actually have any say over the ADA guidelines, it is more than the ADA guidelines adopted the WCAG 2.0 guidelines as just that, a guideline to help. As far as I know, the tool you’ve linked to hasn’t been used in any judgements I’m aware of. Usually when it comes down to making a decision on if something is/isn’t compliant they have people use the actual PAWS tools and show what elements do/don’t work as intended or are otherwise inaccessible. Hope this helps!
The Americans with Disabilities Act (ADA) and, if the government entities receive federal funding, the Rehabilitation Act of 1973 generally require that state and local governments provide qualified individuals with disabilities equal access to their programs, services, or activities unless doing so would fundamentally alter the nature of their programs, services, or activities or would impose an undue burden.2 One way to help meet these requirements is to ensure that government websites have accessible features for people with disabilities, using the simple steps described in this document. An agency with an inaccessible website may also meet its legal obligations by providing an alternative accessible way for citizens to use the programs or services, such as a staffed telephone information line. These alternatives, however, are unlikely to provide an equal degree of access in terms of hours of operation and the range of options and programs available.
Recent years have seen an uptick in federal lawsuits filed against businesses and governments, alleging that their website violates the ADA by being insufficiently accessible to people with disabilities. In 2017, there were at least 814 such lawsuits against organizations in a variety of industries, from banks and credit unions to restaurants and e-commerce websites. The defendants include small businesses as well as major corporations such as Nike, Burger King, and the Hershey Company.