There was a sequel! Alien: Blackout was a mobile game that came out last year and it was a direct plot followup to Isolation. It's essentially Five Nights at Freddy's: Alien Edition, though that might be overselling it. It clearly had a tiny budget. It was an interesting experiment, but very short and simple. I can't really recommend it. There was also a line of comics that continued Amanda Ripley's story. Plus a "movie" adaptation of Isolation that mostly consisted of awkwardly lit and animated character models from the game superimposed over gameplay footage. It was baffling.
But yeah, a true sequel would be awesome. Isolation is still the best implementation of the "stalker" focused horror gameplay concept, and deserves to be iterated on. I've always imagined a sequel having multiple Alien archetypes to hunt and be hunted by, sometimes working as a pack, with abilities and tactics you need to play around with your gadgetry. Co-op would be a natural fit for this style of gameplay too, though maybe as a side mode rather than the main course.
And no way was Isolation twice as long as it should've been. They could've cut, like, two chapters maybe.
Lol, to be honest, very few good games got a sequel this gen. :-(
My main gripe is that Alien Isolation never came to PSVR.
Maybe it's best as one off experiencejust want see it ported to vr.
If you have a PC capable of it,
MotherVR is there for you. There's probably even a way to use a PSVR headset on PC to play it this way, though it might not be an ideal experience. I played the whole game in VR in 2018 and it was awesome.