A post by Tripwire Interactive on Steam warns potential customers of Killing Floor 2 that the upcoming first-person shooter sequel may have some of its gore cut upon full release to comply with regional standards (thanks GBase.ch). Here's word:

It is quite likely that there are some regions where we may be required to make cuts in the future, particularly in the gore system, to comply with local ratings boards, once we get the game into its full release status. Regions most likely at risk of this are Germany (via USK) and Australia (via OFLC). Japan is another possibility (via CERO), but is an unknown quantity to us. To be quite clear: this means that, if you are buying from a region which regularly forces cuts on to games for gore, you may get reduced gore when we go to the full release version of the game.

If we understand the Steam system correctly, if a change is made to a region this will apply to all keys from that region (post purchase).