Sometimes there are issues on which operators and broadcasters tend to disagree, as i have said most probably it will b sorted out soon. Public Broadcasters of different countries have limited funds allotted for carriage fee hence deals fall out if it does not suit their budget, in such cases they opt out of some platforms while remaining on few key ones... Negotiations keep going on and later it gets readded. I think this time ABC Australia will get added alongwith DW TV, distribution company is same for both in India and talks have been on for former's addition on airtel digital tv for quite some time ( i was told this when i mailed distribution company)
You can try connecting with distribution company or DW thru e mail to know reason or estimated time for readdition