He'd recently made headlines when his complete or partially-complete scores for Blade Runner 2049 and mother! were not used. Hans Zimmer replaced Jóhannsson on Blade Runner 2049, somewhat bafflingly proceeding to produce a very Jóhannsson-like final score. The changeover on mother! was more amicable, as Jóhannsson himself felt that the score he'd produced interfered with the movie's atmosphere; after consulting with director Darren Aronofsky, they decided to drop the score almost completely, instead using only distant echoes of it melded into the film's sound design. Jóhannsson instead accepted a sound design credit on the film.
Jóhannsson had completed three additional scores before his passing: Mandy, The Mercy (released just last week) and Mary Magdalene, due out at the end of this month.
Jóhannsson's passing is sad news, especially as such a young age. His music was inventive, haunting, devastatingly emotional and immediately recognisable. His work on Arrival was utterly sublime. He will be missed.