Yep, Roll20 curates the updating of a number of community generated sheets, but they do this on an ad hoc basis. Some popular sheets like Shaped are updated far too often for Roll20 to manage (nor should they). At the Pro level, you can input the code for the build yourself. Kryx usually only sends a sheet to Roll20 when it is exceptionally stable, since he doesn't want to spend time supporting two versions of the sheet.