Airport card stopped working after battery delamination in A1261. Apple gave me a new battery but no love on the Airport card which finally died a little later- but was on the way out, only working temporarily,
Great. Didn't slide the card in enough first go, but went back and all is well!
Also. The three anchor tabs welded to the very front of the case ( the ones at an angle that accept the tiny bolts) had all come completely loose. Glad I noticed this. They must have pulled off when the battery delaminated. I epoxied them back in place before replacing the top case. Anyone with a battery issue should check these or else they may get lost or tumble around inside. Great instructions from iFixit.
Take your time. Keep eyes peeled for weirdness like loose anchors.