They seem to support the current version and the previous two before that. So Mojave is not getting support, but Catalina is at this time. But be careful what you wish for -- the last Catalina security update broke software using openGL accelerated graphics for Apple computers with integrated Intel HD4000 graphics. This includes Google Earth, Google Street view, AutoDesk, RStudio and many web apps. So a lot of people have had to revert to older unsupported MacOS versions just to get any work done.