Yes 
sprintstar, it does look like Atlanta had another wretch crowd last night, much like your family members described to you. Probably helped quite a bit that they faced another Southern team, as it seemed like New Orleans fans came streaming in, based on their  apparel in the  
visible lower level. Had they been playing a team like Seattle or the N.Y. Giants, it might've turned out to be a total "
train-wreck" last night.
Here is a short video of a fairly  recent,  well attended 
MLS match in Atlanta. Notice how well lit the entire stadium is? You can even see the few empty  Upper level seats clearly. Contrast to last night's game were beside the spotlighted playing field and some lower seats, the rest of the stadium was almost completely dark.
Here's a You Tube video of 
Taysom Hills great Thanksgiving  performance.  Please notice at about the 
47 second mark (1st touchdown) and the 
1:12 mark (2nd touchdown) how dark the stadium is. You simply can not see  most of  the crowd. Again, contrast that  with the lighting for the MLS team and you'll notice something is up?
Couple years ago, Breibart (I think) reported the NFL and the networks were considering a silly system were they could digitally fill a stadium with 
computer generated fans. So, for example,  an almost completely empty Liberty Bowl  for the Memphis Express  (defunct AAF) could look  like they have  Super Bowl sized crowd for every game on TV. With modern camera phones, I doubted that ever could happen. News of the fraudulent crowds would get out quickly. But the NFL and Atlanta absolutely unveiled their emergency plan last  night -- darken the stadium so much, that most empty seats disappear. Also, as I noted earlier, they also changed camera angles, to avoid the crowd.