Placing any sappling in the form to make a Mega Jungle Tree, the tree makes a tree tall as a Mega Jungle Tree

Upon placing 4 sapplings in a square, like making a mega jungle tree, when the tree grows it has the properties (the tallness) of a mega jungle tree.

Not sure if this is a bug or not but this is weird and it happens every time I do it... Although when my friends do it on their worlds it doesn't happen.

For me this seems to work with all types of tree.