Comment 24 for bug 60666

Well, the main reason is that bash and bash-completion are separate projects. I think only Debian (and hence Ubuntu) included the bash_completion script directly in the bash package. And another thing is that bash_completion is essentially unmaintained upstream. So splitting the packages makes perfect sense.

Whether bash-completion should be in main is perhaps dabatable, but basic completion also works without it and it is by no means an essential tool (although convenient). So I think putting it into universe is also OK.