If you take away the chest bursting scene and some of the language, Alien could be PG-13 by today's standards.
If Scott is given a lot of control then the PG-13 rating won't destroy my hopes. Honestly, did the R-rating (arguably the most-hyped aspect) of AVPR really help the film at all? It sucked just as bad as the first one for an entirely new set of reasons.
If they get someone else to direct it or it is made in any way apparent that Scott is not involved with the project then there is no reason to think it won't be trash. However, until he drops out he will remain my glimmer of hope for this project.