Foil wrapping meat is nothing more than self juice braising. Adding sauce or juice is just (and as Al said adds additional moisture to speed things up....ie boil the liquid before adding it) for a flavor profile for the braising liquid. It should be understood that meat does not "absorb" the liquid. The act of cooking removes moisture....ie even braised meat can and does dry. Do a little searching for rib cooks and you will see there are many ways to smoke them Smokin Al has a perfect rib post that has gazillian views that is worth reading......
Edit....
PS, here is about the simplest examples I can provide of wrapping....
https://www.smokingmeatforums.com/threads/korean-pork-spare-ribs.301462/
Note the seasoning and sauce can vary to any flavor profile but its very simple. Many people like to put the ribs back on after wrap but I think they go dry. Like zwiller, he waits for it to cool then sears it so it has less of a tendency to dry. Its all personal to the tasty and texture you want.....IE I eat at a BBQ joint that does their ribs hot and fast, IE 350 ish for 2 hrs -1 hr wrapped a little finishing sauce and they are the bomb!