QTBUG-138749 fixed one instance. A quick grep for PROPERTY.*BINDABLE reveals 47 more similar properties across Qt source code which have BINDABLE but not NOTIFY. Out of these, 22 are in the qtpositioning repo.

Note: This grep won't detect cases where the "Q_PROPERTY" and the "BINDABLE" are split across different lines

Suggestion
Check if those properties are exposed to QML, and if so, add NOTIFY signals for them.