TreeView should show new rows after layoutChanged() is called. QTreeView, QListView, and ListView do this and the documentation says that using layoutChanged() is a valid way of updating the views after adding rows.

"This sequence can be used for any structural update in lieu of the more high-level and convenient protected methods."

http://doc.qt.io/qt-5/model-view-programming.html

TreeView does not show new rows after this sequence in the model:

• Emit the layoutAboutToBeChanged() signal
• Add rows to the internal data which represents the structure of the model.
• Update persistent indexes using changePersistentIndexList()
• Emit the layoutChanged() signal.

Attached is a demo application that shows that QTreeView, QListView, and ListView update the view but that TreeView does not.