I've always found that instruction a bit ridiculous in Sensational Knitted Socks, too. Why would you work that stitch and then immediately UN-work it???
Never made sense to me why they don't just say on that last round to 'work until 1 stitch remains' because really it is the same thing. You do
, however, need to rearrange the stitches so that when you do come back to do the instep later on that the stitch pattern is centered on the top of the sock.