The Linux version of Adobe Reader, 9.5.5, is from 2013 and has numerous security vulnerabilities. Recently it was marked as insecure.
There are the free alternatives, evince, okular, etc., but they still don’t support all of the advanced PDF features (XFA forms, scripting, etc.).
So for those difficult PDFs it seems the only option is to run Adobe Reader DC under Wine. Installation automatically is a little tricky with setting some registry keys, but you can simply download the installer and (I think) it works fine running under Wine.
The question is whether it’s worth packaging Adobe Reader DC in Nixpkgs. Currently there are no packages that download programs to run under Wine. The closest are Pipelight, which downloads the Windows versions of the plugins automatically, and PlayOnLinux that includes many recipes for installing software (including an outdated version of Adobe Reader from 2015). There are also binary packages of programs, like Steam.
So: package, or skip?