Hmm interesting question considering I literally just watched this match today. They should have dragged the storyline out a little more and had Batista show up at the PPV after JBL defended and won the Smackdown Championship. They could have had Batista show up on Raw after the draft and Bischoff book him in a match to compete and he gets a phone call right before he's about to go on and leaves. The next week Bischoff calls out Batista, but he isn't at the show. Bischoff says that Batista has no-showed Raw and robbed him and the fans tonight. The following week Bischoff gets ready to suspend Batista for his actions the past couple of weeks and Big Dave shows up via satellite saying that he had a personal issue to take care of, but that's taken care of now. As far as suspending him goes he doesn't take orders from Bischoff and he'll be on Raw next week. The go-home Raw before the Smackdown PPV Batista is shown pulling into the arena, but Bischoff informs him once again that he's been suspended. Batista argues, but Bischoff has security escort him out. Then, Big Dave tries scalps a ticket outside and is shown sitting in the crowd, but Bischoff says his ticket is no good and has Raw wrestlers escort him out. Cena and a couple of other faces try to help Batista, but Bischoff threatens to fire them. Finally, right before the Main Event Batista says since Bischoff won't let him in he's gonna destroy some Raw property. After the Main Event Batista's titantron & music blast and he comes down the ramp w/Bischoff. HHH & Flair try to help Bischoff, but are intercepted by Cena and another face. Batista gives him the thumbs down and Batistabombs him in the middle of the ring. That sunday on the Smackdown PPV JBL beats Christian again for the SWC. He goes to get it from the ref, but Teddy Long's music hits and he comes down to the ring. He goes on to congratulate JBL on a hardfought victory, but that there's no more need for the SWC because it's time to let the cat out of the bag. JBL stares at Long and mouths, "What are you talking about?" Smackdown through a loophole had one more draftpick and that pick is the WHC...Batista's titantron and music hit. Batista comes down to the ring and spears JBL and he poses for the Crowd celebrating w/Teddy Long.
The only problem with your idea is that it breaks the draft format for that year. They went another way with the 2005 draft, a pick was made each night. So, a Raw superstar had to show up as a new member of Smackdown that night. For your idea to work, another Raw star would have been drafted, thus necessitating Batista to be traded. Who in their right mind would trade a world champion? Maybe a contract dispute causes Batista to demand it? I'm not sure.
I would have booked the winner to become Smackdown champion, but I wouldn't have chose JBL. Bradshaw had been all over the Smackdown main event for over a year at that point and I found him quite stale and switching out Batista for Cena really didn't freshen things up. Eddie was Smackdown's other top heel, but he was busy with Rey.
I would have put the Smackdown Championship on Christian. He was white hot at this point and his luke warm face turn and losing to Booker T really did no one any favours. He might have stayed in WWE and become a draw had they not, for lack of a better term, buried him.
It would have been tough to handle. Christian got a pretty good pop when he arrived on Smackdown, he would have had to basically re-turn heel in order to get himself over as a villian against Batista.
WWE likely would not have wanted to invest the money in a Smackdown title belt for this angle though. It would have been great if they did. Christian could have garnered heat by declaring himself the champion of a brand that he hadn't been a part of for three years at that point. The belt could have just been a big Smackdown logo on gold or silver.
The alternative would be sticking with the angle of Teddy declaring they didn't need a Smackdown champion. Christian could have then brought out an old IC title or an old tag title and stuck a big Smackdown sticker on it. I think it could have gone somewhere.
Christian knows well enough how to work a crowd and would have been an excellent foil for Batista. His face turn was so unnecessary at this time, his move to Smackdown would have been better served to make him a top heel. He likely would have turned face later in the year given his crowd reactions.
But to answer the OP's question, the same thing was in the bag as was in the brief case in Pulp Fiction: a storytelling device. They had no intention of starting a new title, they wanted to create tension to start a feud between JBL and Batista.
