Now we don’t know why Sony couldn’t have mentioned this earlier, but the reason for stopping development on the current version of the Xperia Home launcher is because Sony is working on a new Xperia Home app. This was confirmed by Erika Prymus, one of the Xperia Home dev team.
Why Sony felt it needed to start from scratch again on Xperia Home remains a mystery, but perhaps it has something to do with new gesture controls that will be introduced in Android P. We’ll bring you more news as we have it.
Statement from Xperia Home development team
Thanks Devilkin007!