Like I just replied to Jans, it wouldn't be a game-changer. If the group realizes that (which should happen, since two folks just reanimated after being killed by other-than-zombie means), then they'd simply head-cap any regular ol' human they tried to kill.
We know that in the larger scope of things, the enemy is the dead, but these are all dead from the very nature of the zombie, which spreads the plague. If the disease is transmitted via bodily fluids PLUS airborne, then either everyone's f*cked, or people just need to do what they've been doing, and try not to die, which was the original agenda anyway.

I'm just wondering what the possible benefit could be to adding an infection method that only takes place after you're already dead. If it's just for the purpose of introducing a different lore, then I don't think that's going to bode well for the show.