Nah, Cody needs to be winning it himself without any retired lads coming to help him. It would make him look like a bit of a bitch if he needed Stone Cold and John Cena to help him win the big one.
Imagine if a retired legend helped out Stone Cold at Mania 14.
The Backlash 2000 thing made some sense because Austin was still a wrestler and wanted revenge on a noted rival (even though we didnt know HHH had him run down, he'd still been feuding with him right up until that moment), but what beef does Austin have with Roman Reigns? Have they ever interacted?
Just have the usual lads come even the odds with the daft interference and have them brawl to the back to leave Reigns and Cody in the ring for Cody to finish the story.