Hi @handbrakeoff, thanks for the reply. Segments - which are what makes up a road in Waze - have the option of being two-way or one-way, closures can then also be applied to these segments in one or both directions.
While it can be a bit unclear in the app with undivided roads, especially when multiple segments are involved, the closure pin will only appear at the start of the closure/segment (based on direction of travel), or both ends if applied in both directions. As you mentioned, Waze is navigating correctly because the closure has been mapped correctly, though in the interest of providing as clear a picture as possible to Wazers, I have updated the closure description to mention it is a southbound closure, though they do need to click on the pin to see that.
As for dividing the road, I was the one who divided south of Pit St last night, it won’t be live in the app yet. While I do plan on dividing between Meadowvale Dr and Pit St, this cannot be done while there is an active closure on the segments. As for south of node 110450151, this has been mapped correctly as a single segment as there is no physical separation, you can read our mapping guidelines on dividing roads here.
I hope that all makes sense, let me know if you have any other questions. As the map is built and maintained by volunteer map editors, your local insight into this closure is invaluable, so thank you again for reaching out 
If you’re interested in learning more about how we map or becoming an editor yourself, you can learn more at http://bit.ly/WazeEditOz