I highly doubt the predalien would continue to run around the ship after every last remaining predator, that would be sheer suicide. Think about it, there are
hundreds of predators on that ship, including at least 1 elder, possibly more. By the time a few of the unbloods started going missing, they would've noticed something was wrong, they could even possibly have scanners on the ship, that can detect any lifeform anywhere inside.
The predalien would more likely attack a single, isolated predator, & drag him/her off to a descrete location & implant them with an embryo. In time, they would actually become disfigured & slowly begin to morph into an egg (see the original Alien directors cut), after which, a superfacehugger would emerge, capable of impregnating 2 hosts, one with a queen embryo. From there, the queen would begin to lay eggs, & the aliens would probably attempt infestation of the ship, if the predators hadn't already found & killed them by then.