Add Frank's statement

base/doc/ltnews40.tex

@@ -181,6 +181,13 @@ \section{Engine support: important update}
 \LaTeX{} run. Thus \pdfTeX{} continues to be supported for existing material,
 but for new documents, moving to \LuaTeX{} is recommended.
 
+We cannot make statements about the support for other engines such as
+(u)p\TeX{} , as we don't use these programs nor have in depth knowledge of their
+functionalities. To the best of our knowledge, core \LaTeX{} works well with
+these engines, but if and to what extent tagging can be supported will remain
+to be seen. If relevant information becomes available to us we will provide an
+update in future editions of the \LaTeX{} newsletter.
+
 \section{Switch to T1 as default encoding in documents using \cs{DocumentMetadata}}
 
 As it is well known the font encoding \texttt{OT1} supports only 128 characters and