What's new that caused this change, I wonder?
I find this in the man page (emphasis mine):
Code:
quote If set, mailx starts a replying message with the original message prefixed by the
value of the variable indentprefix. Normally, a heading consisting of `Fromheader-
field wrote:' is printed before the quotation. If the string noheading is assigned
to the quote variable, this heading is omitted. If the string headers is assigned,
the headers selected by the ignore/retain commands are printed above the message
body, thus quote acts like an automatic ~m command then. If the string allheaders
is assigned, all headers are printed above the message body, and all MIME parts are
included, thus quote acts like an automatic ~M command then.
...so it looks like you're getting the default heading.
I'll leave it to you to figure out how to assign strings and select headers as defined in the second highlight.