The Oxford English Dictionary definition 1c of the verb copy includes:
to provide (someone) with copies of correspondence, etc., on a
particular subject for information. (Common in office use.)
The entry has this supporting citation from a novel published in 1983:
LaSalle pushed a file jacket across the table, and Harper flipped
through the pages.‥ ‘You'll copy me on all this?’ said Harper.
So the answers to your question are that copy followed by a human direct object is established and recognised and that it has been around for almost 30 years, and possibly longer.