Cingular, not AT&T. https://www.apple.com/newsroom/2007/01/09Apple-Chooses-Cingu...
It's an eerie feeling finding errors or omissions in what is commonly used as an irrefutable source of truth in the modern world. I appreciate the correction though!
Perhaps irrefutable is too strong a word, but if I'm looking for an answer (instead of researching a topic) and want a quick, single source, Wikipedia is my go-to.