alien is kinda holding/ pending prometheus 2. So I shall be working on other things... as much as I love the xeno- and Lt ripley— Иeill Blomkamp (@NeillBlomkamp) October 30, 2015
In case you somehow missed it, Blomkamp's Alien arrived in a flurry of activity at the beginning of this year, just as Chappie was hitting cinemas. Blomkamp released some tantalising Alien concept art online, featuring both Sigourney Weaver's Ripley and Michael Biehn's Corporal Hicks. The internet went crazy, and 20th Century Fox got excited and put the project in development.
Conspicuously though, while there were some lovely images, there never seemed to actually be a screenplay or even a coherent plan, and Blomkamp never seemed clear on whether his film would somehow take place in between Aliens (1986) and Alien³ (1992), or ignore the second half of the original series completely. So while the internet may shake its fist in Scott's direction, declaring that they would rather have a proper new Alien film than any more Prometheus, it is possible that there is more to the Alien 5 abandonment than just Sir Ridley getting his own way.
Abandonment may be too strong a word anyway, since Blomkamp's Twitter line is still that his own Alien is on hold pending Alien: Paradise Lost, rather than a complete shut down. He may be heading for pastures new for the time being, but he might be back at some point. As always, watch this space.