This happens when the ABM runs after the block has been unloaded
for much longer than the ABM interval: in that case, the initial
ABM running chance for a node in the block may become up to 100%.
If moretrees is not present, nature_classic spawns blossoms and
eventually apples on default trees, as it always has.
If moretrees IS present, the code will only spawn apple blossoms on
moretrees' own apple tree leaves, and will only grow new apples on those
trees, not on default trees. In this case, the nature:blossom node is
considered deprecated and is aliased to default:leaves to avoid causing
undefined nodes in old maps.
