Upstream stopped doing that ~6 months ago, so there is currently no obvious reason for not updating it, but I haven't actually tried to do so.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=809997 https://github.com/emscripten-core/emscripten/issues/5488 Sébastien Jodogne wrote:
As the package has not been updated for more than 5 years, I fear this package should actually be considered as orphaned
https://www.debian.org/doc/manuals/developers-reference/pkgs.en.html#package-salvaging