Update status to correct experimental wording

Author: Pennycook

sycl/doc/extensions/experimental/sycl_ext_oneapi_reduction_properties.asciidoc

@@ -49,12 +49,12 @@ This extension also depends on the following other SYCL extensions:
 
 == Status
 
-This is a proposed extension specification, intended to gather community
-feedback.  Interfaces defined in this specification may not be implemented yet
-or may be in a preliminary state.  The specification itself may also change in
-incompatible ways before it is finalized.  *Shipping software products should
-not rely on APIs defined in this specification.*
-
+This is an experimental extension specification, intended to provide early
+access to features and gather community feedback.  Interfaces defined in this
+specification are implemented in {dpcpp}, but they are not finalized and may
+change incompatibly in future versions of {dpcpp} without prior notice.
+*Shipping software products should not rely on APIs defined in this
+specification.*
 
 == Overview
 
@@ -87,7 +87,8 @@ implementation supports.
 |Description
 
 |1
-|Initial version of this extension.
+|The APIs of this experimental extension are not versioned, so the
+ feature-test macro always has this value.
 |===
 
 === `reduction` overload