Well the current route 112 would mean no current need for route 11, and route 95 is definitely ceasing operation. I would have heard something if route 31 was also stopping
I'm not sure how you gather the current route 112, means no need for route 11? But your really comparing apples with oranges!
The current Route 112, doesn't mean no need for route 11. Route 11 services Victoria Harbour, which 112 doesn't, and is needed to service that and carter to the heavy peak loadings.
Route 31 is a totally different scenario , it's basically a service to provide addtional lunch time capacity along Collins St, brought about when route 11 and 12 were combined in early 2000s. So it was created to ensure demand can be met around lunch time.
When route 112 is split, there no longer a need for route 31 anymore, as Collins St goes back to having route 11 and route 12 along it, as it did before the routes where combined, thus Route 31 no longer to provide additional lunch time capacity.