They took the closed XPack code and put it into the open source Elastic repo, but under a commercial license. It muddied the waters for anyone looking to use or contribute to the open source.
Prior to this move, the default install of the Elastic Stack was 100% open source. X-Pack had to be intentionally installed as a plugin.
Now the default install includes X-Pack, and you have to go out of your way (assuming you even realize that there is difference) to install the 100% Apache 2.0 licensed version.
