Alternately, it could designate the upgrade-or-lose-patching deadline as the release of the CBB upgrade which follows the one for the Anniversary Update's. (Initially, Microsoft said that several CBB builds would be supported simultaneously.) If that's the case, companies may be able to run 1511 until mid-to-late 2017, or as long as 20-24 months.
The muddy schedule, analysts have said, is probably due to Microsoft's finding its feet in the faster development and release process. That has caused the once-regular release pace -- as described by Microsoft last year -- to become messy and clouded with uncertainty.
In other words, much more like the old Windows upgrade calendar.
Sign up for CIO Asia eNewsletters.