The online docs are regenerated daily from the current repository, so the inclusion of typing.Deque in the doc is correct, given that it has been added to the module.  IDLE aside, new features in bugfix releases are limited to provisional modules, such as typing.  I believe this should get a 'New in 3.6.1' (or 3.5.?) note.

Some installations include a local frozen copy of the docs.  The frozen copy will not include the rare (and admittedly confusing) feature added for a future release.  But it will also not include the much more common corrections and clarifications added since the release.