The problem is that facehuggers couldn't do that before, it needed hours to implant whatever it was that it implanted. Egg, tumor or as of recently Plagiarus praepotens.
Unfortunately newer information does tend to override old. It does cause some issues however, like that Marachuk should have then already been implanted with a chestburster as well as the other poor sod who was also killed during the removal surgery, it should have been too late. Also then those two huggers should not have been alive to attack Ripley and Newt.
Ripley 8 would almost certainly been implanted as she was exposed to the facehugger longer than Lope was, though we don't know if it got the tube in or not. Though speaking of, that is an odd case for Lope because the tube wasn't even down his throat, evidence by how he was clearly able to shout "get it off me".
So who knows how what huggers can do now. Its like magic macguffin these days..
The Cold Forge is a really good novel, but unfortunately that also continues the instant implantation as well, I really hope newer novels avoid the direction Covenant went in but it seems it might just be the new status quo.
