I think L4B has it right. Not that you don't have the background, but it seems like there has been a BIG shift to the customer service side of the interview. PERHAPS what they have done is brought back the phone interview process because of such a low hire rate. Meaning that since so few are being selected they are going back to the phone interview as a way to weed people out and, as previously stated, save the time and expense of a face to face.
You'll do well though, so I wouldn't sweat it.
You'll do well though, so I wouldn't sweat it.