Maybe they will add the stip sometime between now and the PPV, but that seems unlikely to me. You'd think they'd announce this earlier. Anyway, they've never had a 6 man tag in the chamber, it's an option on the WWE 13 game and it would work great here and here's why:
Imagine it starts out Ryback vs Reigns. They battle back and forth evenly. Time for a random combatant to be released from a pod. Out comes Ambrose. Ambrose and Reigns double team Ryback. Time for another random combatant, it's Rollins. The Shield finishes off Ryback before any of his team members enter the match. Sheamus then Cena enter the match but can't overcome the 2 on 3, Shield wins. It let's The Shield win an important math without making the other guys look weak at all. I played this type of match with my buddy the other day on the game, and the same scenario happened to me.