Amazing feature! It put a spotlight on the accessibility of the web and I think that’s wonderful to see these things taking more seriously. It is also soo good for SEO and no one can hate that 
I would love to see a list of text that don’t comply with the AA or AAA rating.
It would be optional to comply on that to respect the freedom so dear to our designer heart but you would see in one place all the instances that are not legible and it would help lots of designer pay attention to that kind of thing (it is in the cooler panel of type-setting but a bit of redundancy here would not be a problem I think )
Thanks you Webflow ! Great work !