OK, reop is safe again.
diff --git a/Lib/re.py b/Lib/re.py
index 5c8827a..d1df766 100644
--- a/Lib/re.py
+++ b/Lib/re.py
@@ -1504,5 +1504,5 @@
 
 # Replace expand_escape and _expand functions with their C equivalents.
 # If you suspect bugs in the C versions, comment out the next two lines
-##expand_escape = reop.expand_escape
-##_expand  = reop._expand
+expand_escape = reop.expand_escape
+_expand  = reop._expand