If the sending address site has set a strict DMARC configuration then
you basically have two options. One is to modify the headers and
forward it through the mailing list. Or two it can be discarded or
rejected. Forwarding a message from a sender site with strict DMARC
set will be seen as a forgery by the recipient site receiving the
mailing list and many sites, Google for one, will reject those
messages.
If valid DKIM is ok, then you have a third option: Do not modify the
message. Specifically, do not add a subject tag and do not add a
footer.
I believe the NetBSD lists operate this way.
I find the sender rewriting icky. If it rewrote to a per-user
forwarding address at the mail host, so that sending to that address
went only to the user, that would be ok, but combined with incorrect
List Reply-To: it becomes all too easy for private replies to end up on
lists. To me that is a bigger problem than just not allowing addresses
with strict DMARC policies to be on lists :-)