While I do favor Cody over Sandow and though I like the idea, it can't happen based on two consequences:
1. There are few main event heels. I noticed this when they had the All Star MiTB and realized the heel counterpart was treated as secondary and full of midcarders. The only dependable heel main eventers right now are Ryback, ADR who is boring the crowd to tears, and The Shield sort of. Henry and Dolph just went face (the former being a huge mistake to turn imo), Lesnar is part time and clearly doesn't care much, Big E. doesn't fight as regularly as he should and Bray Wyatt is a wildcard at this point. Sandow needs to pay off as a heel at this point, and making him lose the case just crowds the ME scene with another face in Cody (although this would balance out if Randy goes heel, but that feels a bit further away).
2. Cody has been losing too often, and to make him a face and have him lose high profile matches so early feels like a bad idea. If they have a first match, Cody should either win (in which case the MITB should not be on the line), get a DQ or countout win or lose dirty.