The wording makes me think that's it's purely about allowing non-hygienic macros[1] in some sensible way. (At least a quick glance at the Rust book/manual suggests that macros are always hygienic in Rust.) Hygiene is a good default, but it does prevent certain other useful uses of macros.
It's the opposite: macros currently leak their internals in certain circumstances with unsafe and privacy/name resolution, i.e. are slightly non hygienic (they are properly hygienic with respect to local variables, which is the major advantage of hygiene). The changes would make macros more hygienic in those aspects.
[1] http://en.wikipedia.org/wiki/Hygienic_macro