If GW were working on a 'standardised' ruleset that could just be errata'd every so often then the current fake/leaked ruleset would be a terrible start. By continually adding new material to such an in-depth ruleset we will end up with the 2E problem all over again.
A standardised rule model would need to be much leaner, almost 3.5E (3E + TAR + Tank rejig) in specification. Depth (Cityfight, Apoc etc) can then be added via supplemental material and the community. The 6E we have scales poorly at smaller points, has too many charts, too many pointless additions (EV, Actions) and takes too long to set up the game.