How do they create the AT&T Video Bill?
I use a script for After Effects (CompsFromSpreadsheet) which generates compositions using the data from a spreadsheet. We use it to batch create graphics with different values - like in the ad. 

The script can add different files into the animation at different times, so they probably have a database of all the possible phrases.

The script as it stands couldnt be used to fully automate the process as you still have to specify where the spreadsheet is, but you could easily create a simmilar script which would look for new spreadsheets, apply the data to a template and start a render. 

That being said, I wouldn't be surprised if they had their own in-house software.