I hope you're right, but given all of the studio's history of recycling old transfers for new formats, I'm not sure I share your confidence. (How many laserdisc transfers were ported to DVD unchanged in the early days of THAT format.)
True, using the same transfer wouldn't given owners of the HD-DVD version a reason to double-dip, but it isn't like they are the target audience for this release. So much of the growth in BD has taken place since the end of the format war (as HDTVs become more mainstream and normal people actually have a reason to pay attention to hi-def content) that I daresay most current Blu Ray owners have never heard of HD-DVD, much less collected the format. If nobody who owns the HD-DVD release buys the upcoming Blu Ray it probably won't make much of a dent in Universal's bottom line. They just need to produce a disc good enough to entice people to replace their DVDs, or to buy the film for the first time on BD.