Create two layers and make the topmost layer half transparent. Now choose the perspective tool, and change the perspective of the topmost layer. As you see, the transparency is removed when using this tool. Sometimes this is useful, but not in the case you want to match the topmost layer to the bottom layer, by e.g. creating a panorama. By previous versions, i always set the transparency of the topmost layer (or i choose something like 'multiply filter') and then i use the perspective tool, so i see the backlayer through the toplayer.

Is it possible that this feature comes back? Maybe this can be an new option by the perspective tool.