Cherry trees, when grown with bone meal in a way that they can overlap, can sometimes cause some of each others' leaves to decay. This is easier to see with a high random tick speed with tile drops on as the sapling items appear faster. This does not seem to happen with any tree type other than cherry trees.
Can confirm. When setting your randomTickSpeed up (10000 in my test) and plant a few saplings next to eachother, you´ll look at the top of the tree "cluster" and see some saplings laying on top of the leaves. Made a recording to visualise, you can see a sapling laying there at the end. Sadly the file size limit doesnt allow me to make it any longer, so I cant prove that it happened on its own
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