"Shaznay, you worked with Mutya Keisha Siobhan on their comeback a few years ago ..."

Music The All Saints ID interview also yields this on the topic of the proper Sugababes:

Shaznay, you worked with Mutya Keisha Siobhan on their comeback a few years ago. From the outside, how did you view the dynamic of a girlband getting back together after a difficult falling out?
Shaz: I was really happy for them! Before we were even signed to London Records, when Mel and I first started All Saints, the people we initially worked with went and found those first three girls, Keisha Siobhan and Mutya. We've kind of done the same path as them so for me to work with them was lovely. Their voices together have a distinctive sound, like ours. I enjoyed seeing the three of them back together. Loved it. I champion those girls.

They'd be good to tour with.
Shaz: Yeah!
Mel: They would actually…

Sob.  Oh sob.