Possibly, but that means [at this point] finding either a euro parts phone, or waiting until an aftermarket company can source just the front facing camera pieces.
Chances are the traces and connections are all intact though, unless AT&T decided to be really annoying.
EDIT: As far as software that will take advantage of the FFC, the only one I know of is VzoMobile. Which apparently is no longer free.
AT&T HTC One
Asus Transformer Prime
"We want monies. You have monies. Give us monies.” -- Phandroid (poking fun at Gemalto lawsuit)