I think at this point it's pretty safe to assume the comic has little to no bearing on what happens on the show.
It would make for interesting drama for Eugene to be bluffing - Abraham would not take it well. It also makes the most sense for the show, since finding a 'cure' really isn't in the cards. But Eugene gives them something to focus on, and it also provides a way to get Gareth back to them, since they already blabbed the whole thing to him, including that they were trying to get Eugene to D.C.
Really?? while the show doesn't follow the comic 100%, overall the show has been pretty aligned with the the comics. We even got a bearded Rick!!