There are many priorities, this is true. But it has come in a joint statement between Queensland Government and BCC. In contrast, a proposal to upgrade of the Doomben line with duplication and extension has not.
A quick way to tell is to propose such an upgrade to QR and the Transport Minister and see how they react to it. AIUI TMR has no plans to duplicate the Doomben line. They do have plans for potential conversion and want funding to study it, and this is public knowledge.
In other words, they want to consider a bus conversion (possibly without looking at a rail upgrade) and many members here want to look at a rail upgrade (possibly without looking at a bus conversion).
In general, good strategies consider all major options, and a good way to capture that is to consider applying the MECE framework to the problem solving approach:
Image Credit: StrategyU (2025) What is the MECE Principle? Understanding Mutually Exclusive, Collectively Exhaustive - StrategyU
Perhaps the way forward here is to consider both, which would resolve the situation. That way we would know for sure.