spoilers ahead I felt like the character conflict arcs were contrived and ultimately the idea of learning a language makes you a pre-cog fell flat for me. In science fiction, the big idea goes ‘woo!’ or the characters go ‘woo!’ but in the case of Arrival, nothing really went ‘woo!’
But maybe I’m wrong - what was I missing about Arrival?
I thought Arrival was a good spin on time-travel. The information travels backward in time, but it is resolved - a consistent timeline results (as far as we witness it, at least). Good sequel could be to fast forward whatever it was . . . 3 millennia and see the intelligent cockroaches from Earth arriving to save the hecapods after the knowledge the hecapods bequeathed led the humans to promptly self-annihilate, opening the path for cockroach evolution.