Most of the time when I look at a sapling, I don't have a good idea of what kind of tree will grow. "Is this a pine tree? A deciduous tree? A palm, perhaps?" If there was more information in the preview, maybe we wouldn't have to guess so much when choosing the perfect tree for a particular planetary colony. Please consider this for 1.0 or post-1.0!
This used to be the case, somewhat, not sure why they removed it. Essentially the item sprite would be cut in half, one half was the sapling pod, the other was a preview of what was in it. Again, I don't know why it was removed.
Are you referring to the old tiny preview that showed a bit of bark on the left and a bit of foliage on the right? Like this? If so, I made this suggestion when we still had that system for saplings; I actually found it still insufficient. A lot of them looked really similar despite the full-grown trees looking distinctly different (eg., pine trees vs. certain deciduous trees). I hope the reason they removed it is because they're working on something better