The studio has intentionally avoided confirming or denying the game's canon status
In an interview for Metro, the game's 'Console Design Lead' Clive Lindop stated that the issue of canon was one that they'd put to one side on purpose.
GC: The other problem with games focusing on Aliens is that the creatures themselves were much more straightforward in the sequel,
more-or-less straight analogues of ants or other insects. But the
alien in the first film was meant to be a lot more complicated, is
that something you’re also going back to?
CL: It’s one of those things where if you get deep into the subject you find out that there’s a difference between the popular
perception and what you know from digging around. There’s a lot of
stuff in the original script that never made it onto screen. And so
we always avoided the question of canon to a certain degree because
we’re never going to retcon the story or suddenly make massive
rewrites to what happened in it, and as far as the creature is
concerned Cameron in effect, for the audience that had never read
previous scripts, filled in an aspect of the alien’s existence that
hadn’t previously existed.
And if you take that as read then yeah, you kind of have… what you understand as the audience about the about the alien is mechanical.
You don’t understand why it exists but you understand how it functions
and its life cycle. But you don’t necessarily know the… from our
point of view it was never about trying to add new canon or explain
something it’s about what is it actually like to be the subject of his
attention?And that’s something that, without a huge amount of military
hardware, you’ve never seen.
Alien Isolation interview – ‘we keep scaring ourselves’
This was also discussed by the game's 'Creative Lead', Alistair Hope in an interview. Note how artfully he dodges the question.
The details about Amanda Ripley and the art direction appear to be faithful to the spirit of the early films. Have you had any discussion
with FOX about whether Isolation will be considered a canon entry in
Alistair Hope: We really wanted to place our story as close as possible to the events of the original film. We realised that in Ellen
Ripley’s daughter, Amanda, we had a character who was closely tied to
the first film, but whose story had yet to be discovered. We asked
ourselves: “When the Nostromo went missing, who would care enough to
keep searching for answers?” This led us back to Amanda; she would
FOX has been extremely supportive from the moment we pitched the idea of the game to them. We’ve received a huge amount of production
design archives from the original film which has provided an enormous
wealth of additional material from which to draw upon. This is very
much a game inspired by the first film.
Behind the terror of Alien: Isolation – exclusive interview
He then takes precisely the same tack (e.g. highlighting that the game doesn't conflict with the existing canon, while not actually confirming its canon status) when asked the question in a later interview.
Strategy Informer: Players will be taking the role of Amanda Ripley. She was mentioned in Aliens, the second film, in the special edition
or an extended cut. Does that mean players are to consider Alien:
Isolation as canon?
Al Hope: So this all came out of, when we started. I really wanted the game to take place as close as possible to the first movie,
because one of the things that we wanted the experience to be was
about Ridely Scott's original alien: massive, terrifying, lethal. We
love, love, love, love the environment, the 70's view of the future,
that was what I wanted to make.
So in terms of story I wanted something that was kinda connected to that first film and we kept thinking about it and asking questions,
“okay, the Nostromo has gone missing, who would care?” Weyland-Yutani
would care, they said they cared in Aliens -- it was an expensive loss
for them -- but we felt we needed something that had an emotional
connection. Then realising that Ellen Ripley had a daughter that was
revealed in the director's cut of Aliens, that meant that there was
this person out that, when Ellen went missing, wanted to know what
happened. It seemed like her story had never been told and this was
“wow okay, this was amazing, she'd wanted to know!”. So in our story,
when Weyland-Yutani believes someone's found the flight recorder, they
send a small team to go and collect it; Amanda is one of the
volunteers to go to the station.
IN SPACE, MICHAEL WESTGARTH TALKS TO ALIEN: ISOLATION'S CREATIVE LEAD AL HOPE