'Mantis'-type entities are reported during abductions (at which point, it depends whether you feel there's enough evidence to convince you it's a literal experience or something else), but '
Prometheus' is very unlikely to feature anything like them.
In fact, I doubt it's going to include any UFOlogy 'lore', whatsoever. It's just using the 'interventionist' hypothesis as a springboard for its own unique story.
However... I've always found it interesting that LV-426 is set here:
http://en.wikipedia.org/wiki/Zeta_Reticulihttp://en.wikipedia.org/wiki/Stars_and_planetary_systems_in_fiction#Zeta_ReticuliFor reasons of it being the system allegedly imparted to Betty and Barney Hill, during their famous abduction case, as where their abductors apparently came from. I won't bore anyone with the details here, but if anyone's interested:
http://en.wikipedia.org/wiki/Barney_and_Betty_HillSo, yeah, it's
feasible to include UFOlogy stuff in the '
Alien' franchise for that reason - but not very likely.
Would be interested if that case was what prompted the original writers to make it Acheron's location, however...
Whatever the case, so long as they make it good and entertaining, I don't mind what they base the story on.