I Uploaded UIX 2 theme and in change log on enxf.net it is written that UX 2 addon is not required to work theme properly
But after uploading the theme it is asking for UIX 2 addon
Its for only updates, like if you had the UIX 2 addon installed previously than the new update won't require an update of UIX 2 addon, but if you are doing a fresh installation, you will definitely need the addon to be installed.