Here's my proposed doc change for 3.6.0. Any concerns about wording? (The change to remove the line from _bootstrap_external.py will be separate, for ease of cherry-picking.)


diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -806,6 +806,10 @@
 
    .. versionadded:: 3.3
 
+   .. deprecated:: 3.6
+      Use :mod:`site` configuration instead. Future versions of Python may
+      not enable this finder by default.
+
 
 .. class:: PathFinder
 
diff --git a/Doc/using/windows.rst b/Doc/using/windows.rst
--- a/Doc/using/windows.rst
+++ b/Doc/using/windows.rst
@@ -823,6 +823,14 @@
       * Adds ``pythonXX.zip`` as a potential landmark when directly adjacent
         to the executable.
 
+.. deprecated::
+   3.6
+
+      Modules specified in the registry under ``Modules`` (not ``PythonPath``)
+      may be imported by :class:`importlib.machinery.WindowsRegistryFinder`.
+      This finder is enabled on Windows in 3.6.0 and earlier, but may need to
+      be explicitly added to :attr:`sys.meta_path` in the future.
+
 Additional modules
 ==================