Being that it was supposed to be an intermediary stage, the idea was that this is how the PredAlien could spawn as many of her brood that quickly seeing as there just wasn't that many facehuggers to go around on the Scout ship.
We haven't seen Praetorian do that but then again they also haven't ever appeared on film before. So as far as we know this could be a trait unique to the PredAlien or even this specific PredAlien. While the PredAlien is an intermediary stage in Requiem between Warrior and Queen, it's up in the air as to whether its a praetorian or not, be it that its a praetorian with Predator traits, or it's a Hybrid that happens to serve the same function as a praetorian. We just don't know and the film never addresses it seeing as Chet simply wasn't alive long enough to make the transition. Being that its also the only cinematic appearance of the PredAlien and maybe the Praetorian, we just don't know if this is a mutation, or if this is just something the PredAlien or Praetorian genus is just capable of doing.
Without another film addressing it we just don't know. And the extended media doesn't help because what exactly spawns a Praetorian is inconsistent; seeing as it can come from any Alien seeing as it gets enough Royal jelly, it's pure-breed, Queen Facehugger, or it's just a natural stage of the life-cycle. We don't know if the barfing is caused by point of origin or if its just natural.
The other PredAliens don't do this, but then again none of them are alive long enough to do that. Nor do any of them outside of Chet encounter any pregnant creatures. With a Queen usually present we also don't know if this trait is specifically in the absence of a queen or not and if this trait is unique to the hybrid or if every Alien could.
The films never addressed it nor did any of the EU and it likely isn't the Predator's reproductive system seeing as they wear codpieces (including the EU females) meaning they do protect something down there. So that system is probably eerily similar and likely doesn't including oral rape.