Who think it will be stay ? When RS4 RTM arrived to GA, all what belong to insiders should disappear.
People who receive SCU through WU this month, will receive this build and (I guess) immediately after installed it will receive a patch (ZDP) that corrects that as happened with the build 16299.15. even so, for a brief time, millions of PCs will have that configuration managed by the insider program, it seems incredible that Microsoft does not mind that.
Looks like the semi-annual release cycle only causes a constant degradation of quality in RTM builds. Doesn't look promising...
I have mentioned it in chat. Check if dism /online /get-currentedition gives you an error message instead of "Current edition is :" message. Polish and Czech are affected as far as I know.