It has been announced and will be released at some point. You bought the stage fully knowing that the editor was not available at that point in time. Would you rather have a buggy piece of software or something stable with which you can actually work? What difference will a couple of weeks make?
Kemper announded summer, but never commited to a precise date. As such, you really don't have the right to complain in my opinion.
Be happy that Kemper is providing free upgrades, which in the past dramatically improved the capabilities of the machine. The hardware is now 7 years old. Do you know of any other company in this business which provides free updates over such a long period?