I actually just started playing the game. However, I wanted a more commissar lord-type kind Warlord. Are there any news of expansions that hopefully adds another Imperial Guard Warlord?

The next AM Warlord is an Inquisitor - beyond that, we have no previews for the next Cycle or what it may hold.

None yet, altough I do think that it's likely our next AM Warlord will be either Yarrick or Creed.

Next pack will be Torquemeda Coteaz as the new Astra Militarum Warlord. He is an Inquisitor.

You can see a preview here:

https://www.fantasyflightgames.com/en/news/2014/11/4/the-threat-beyond/