This may seem strange, but Erika Prymus, developer of the Xperia Home team, responded to this, and she stated that Sony is now focusing on a new Xperia Home application.
The reason for this is not clear, but GSMarena guess may be related to the new gesture control introduced by Android P, as well as the full screen adaptation.
Perhaps this new launcher will run on the Xperia XZ3, and by convention Sony will release the Xperia XZ3 at the September IFA show.
According to previous news, the Sony Xperia XZ3 uses an 18:9 aspect ratio screen, with 3D curved glass on the back, and dual cameras. It will be equipped with Qualcomm Snapdragon 845 processor, equipped with 6GB of memory, and may provide 64GB/128GB of storage capacity.