Interesting, though all-list PR perhaps shouldn't be the sole alternative and perhaps a range of proportional electoral systems like MMP and STV could also be given and states get to choose from them. Also do states currently have the option of being unicameral (Nebraska irl is unicameral so would this force them to abandon their system)?
I'd certainly prefer STV to the more problematic party-list PR, and I personally oppose unicameral legislatures (just look at Queensland), so I would hope bicameralism is required.