It is the same, but I appreciate it may not seen that way. It is to do with how it is designed. If you cut a tree block, leaves around it are converted to orphans. Orphans decay.

Historically all leaf would consider decaying and performance wise in leafy areas, it was horrific, so it was changed to this. It seems the leafs aren't correctly orphaned when the tree was cut. If you press debug (f5), you can see the technical name of the node you're pointing at. If you cut tree, it changes to the leafname_orphan. These can decay. My assumption is the ones not decaying were not orphaned and won't have orphan in their technical name.