According to this website anyway, who have a reliable track record when it comes to leaks.
Say what you will about Christina and her singing, but if this is true, I can’t think of a better singer to pay tribute to Amy. She slayed that Aretha tribute. And I don’t see how she could work in belts and shrieks into Amy’s songs (excluding Rehab and Valerie).
Source: Twitter @ Seven Foot Sounds