That's crazy. I knew that one of my college friends had interviewed at Epic as a new grad, but he didn't go any further with it. Sounds like a really strange company.
It might be the case that salaries won't become truly bimodal. It seems like there might be "tiers" of compensation which are based on levels of competition between similar companies. SV startups tend to pay less than Google or FB, but their compensation packages are typically within the same ballpark of each other. Perhaps the bimodality is most notable for new grads, since they typically don't get hired at mid/small companies.