Relay is positioned as being complementary to React, and React itself currently works on IE8+. There is talk of phasing out IE8 compatibility from React (probably later this year), but as of today it works on IE8 perfectly fine for us.
None of this tech requires much promotion since it's clearly the new hotness, but there is a silent majority of developers that would appreciate knowing when they can start paying attention professionally. Hopefully soon all JavaScript projects will include a list of supported platforms alongside their corner GitHub banner.
