They’ve done this since they were added to Legacy Console Editions all the way back on December 19, 2017. In fact, there’s a picture on the Minecraft Wiki of the fallen trunk generating on water, and in the background is a lone stump like you described. The trunk portion can also generate in caves or hanging off of a ledge if the circumstances are just right for it to do so.
They’ve done this since they were added to Legacy Console Editions all the way back on December 19, 2017. In fact, there’s a picture on the Minecraft Wiki of the fallen trunk generating on water, and in the background is a lone stump like you described. The trunk portion can also generate in caves or hanging off of a ledge if the circumstances are just right for it to do so.