It would appear that these sorts of private networks are...

It would appear that these sorts of private networks are becoming an increasing problem for the NBN and the government.
https://www.itnews.com.au/news/nbn-co-claims-rsps-can-hold-it-to-ransom-486533

The ACCC has already forced TPG to allow other carriers to use their FTTB product, and Telstra to share its Velocity Fibre network.
The new 10gig Adelaide Network will also probably make an appearance in front of the ACCC to determine if other carriers can use it.
Despite this I don’t know of any carrier that has chosen to resell TPG FTTB or Telstra Velocity. The government doesn’t want cherry picking by carriers and the ACCC wants all carriers to have access to telecommunications assets and will force them to share.
The other issue coming to a head is that NBN will also be offering FTTP in many NBN areas for an additional cost
It looks like RSP’s will be legislated to offer NBN fibre before their own product, too..
So expect to see more protection of the NBN.
The NBN are also looking at providing a product to provide mobile backhaul for carriers.
The mobile carriers will throw up their 5G small cell and probably provide a cheaper faster solution than a direct NBN connection..
Dear customer,
Would you like the 10Gig fibre connection from NBN for $1000 per month. Or the TPG 10 Gig  for half the price, or the Optus one on their fibre, or the Optus one that uses TPG wholesale.... it’s going to get messy...