Pretty much. Upstream has basically rewrote the whole distribution
mechanism to depend on Composer, which made it very hard to package new
versions, as composer isn't itself packaged in Debian (or wasn't, last i
checked):
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=714118
I have therefore orphaned the package:
https://bugs.debian.org/798500
I do not use drush anymore, either. You are welcome, of course, to take
over the package! :)