He seems happy about it instead of concerned. It's not that he's happy they're Confessed--more that Kahlan didn't decide to try and organize a rebellion. It probably wouldn't work, of course, but Darken doesn't like the idea of having to deal with the Confessed.

using the words of the devotional to bring her mother back. Which means, now Kahlan's said the devotional to Darken... ;)

Can't wait to see what happens next. Glad I'm keeping you interested :D