They did the same with Anakin and Obi-Wan's jedi Starfighters, and they'll no doubt do the same with another Cloud City set once the Carbon Freezing Chamber set has moved on.. I don't understand it.. People want to buy/collect sets that go together.
Unless it was delayed as I think was mentioned, and was due for release this time last year.. would the AT-AT still have been around then? Either way, the Hoth Attack set seems like a pointless accompaniment for the UCS set, when an extended Echo Base would have been much more desirable, or something more Empire-focused. I guess it's meant to be an add-on you can buy multiples of, like the set that was released alongside Helm's Deep to extend the wall..
Here's roughly what I hope for the minifigs if the Death Star is just a remake.. (with Vader's new helmet, Stormie printing more like the FO troops, etc.)
But like others have said, hopefully the 'final duel' part will be left out since it now a great standalone set. That would leave room for other figs like Imperial officers (dark grey & black) and technicians (light grey) etc. in place of Jedi Luke, the Emperor and his royal guards. If it is a playset remake, it might be a nice idea to try covering the exterior so it looks more like the Death Star when on display, with removable/opening panels to access the interior; just to distinguish it a bit from the previous model.