So I think I might have stumbled across some future sim-only deals. Some promotional images showed up briefly on the 28th of September which have now been removed. However, you can still see them on archive.org if you scroll to the bottom of the page and click on the "Sim Plans" tab: https://web.archive.org/web/20180928093333/https://www.optus…
They advertise the following sim-only deals:
- 30GB for $35/month
- 50GB for $45/month
- 80GB for $55/month
My theory is that these will be offered once the current deals expire tomorrow.
Nice Find!