I can fully understand the question and I will try to answer it without nourishing a flamewar and stay strictly with facts. Except for one personal thing, that needs to be stated here: Santa is not an easy person to get along with and work with on IRC and he knows that. We appreciate his work, as many users do, but maybe our work with him will come to an end.
That being said, we are not quite sure at this point in time what will happen. A couple of weeks ago we talked about our upcoming release with Santa. As we do not feel comfortable to base our release on kde-next as a only default, we tried a compromise: We offered to release two flavours, one with debian's KDE, one with kde-next from Santa. Unfortunately we could not reach an agreement, because Santa did not understand nor accept that we owe it to our users to leave them the choice to also follow debian on KDE if they like.
Things went back and forth and back again for hours without getting anywhere and we made it clear that we will not move from this position. In the end Santa came to the conclusion that he will probably leave siduction behind at some point. He let us know, he had been thinking about this for a while already. He did not give a date for this or make it a clear decision yet.
That is the reason why I have not yet informed our users about the state of affairs with kde-next. We will ship a release, hopefully with plasma 5.5, if debian provides (most likely it will be a dev-release and we hope it is possible within the remaining days of this year) If Santa steps up and agrees to do a kde-next-update we are willing to also ship that as another flavour of kde developement for our users to choose.
I would have been happy to answer this question with more clearly, but this is all we know at the moment. Should kde-next not be updated, we will provide our users with means to go from kde-next to debian's kde. We have not decided yet, when this will happen, it depends on the necessity. This process is a bit more complicated than just a dist-upgrade with an altered sources list (which will not work), but it can be done and we will assist users in the process, should it become necessary. So please do not panic, there is no reason to do so.
