If the cable company disconnected the AT&T service at the NID, then you'd be responsible for reconnecting it - or paying AT&T to come out and do it.
If you were previously able to plug a phone into any jack in the house and have it work with your cable voice service, then your DSL modem won't work out of the box. -- University of Southern California - Fight On!
A tech will likely go out to your house (unless it has had U-Verse before) but they will NOT go inside and do anything for free.
On an install for an address never served U-Verse they are required to send a tech to verify signal up to the box on the house.
If you had a previous phone line in the past it should be simply plug your modem in and golden. If not or not original owner inside wires may need changing.
In my case, I took the telco box off side of my house 6 years ago as got rid of all landlines. When they came out he installed a new one to the location I wanted (on other side of house, as I did have a ground rod on that side too for him to use).
I asked him what they normally do on self-install and he replied verify the signal gets to the house and no major bridge-tap. Beyond that not they job for getting it inside unless you opted for professional install.
So that said they come out to validate you have a telco box on the house and that signal to it is live but from that they are not responsible for anything else without charging. (unless you get a cool person).
So if you're home and can watch outside the entire day of your activation or even the day before in case they come early you might catchem and he might be able to hook the wires back up for you or tell you which ones to use. Odds are if you put a note on the box if you're not home asking them to please do they will to but they won't go beyond that box on your house...