Remember when TNA went head to head with Raw and they somehow landed Jeff Hardy, the biggest actual draw in WWE the year before?
Didn't mean a thing.
Luger in 1995 either, really. It's cool for the fans, and I understand you want a show that hooks people enough to create a culture and a buzz around the product, and a surprise jump is one way to do that. But its not the only way. Reminds me of watching the Royal Rumble when Styles debuted, and people grumbling after the show because they'd have liked another surprise in the Rumble. It's a short term artificial high, these surprises. They did one with Moxley last time that they likely can't top, so I think managing expectations would be wise - the show shouldn't be deemed a failure if CM Punk doesn't show up.