I don't actually think state borders need to be reopened before international. The state borders are no longer based on health measures and mostly political. Reopening international borders to States that are open could happen before state borders reopen. Its just the states with closed borders will be unable to participate. It may force state premiers to reconsider their border restrictions.
I hope state borders reopen but I think there needs to be a bigger driver for them to reopen.
I see it the exact opposite! International arriving pax can be quarantined. Once completed they should present no risk to the community.
Opening state borders means you can have asymptomatic folk travelling and starting a cluster... as we saw in regional Victoria last week. It just takes one person to paralyse an entire town, shutting businesses for days, forcing thousands to queue for hours for testing... it makes sense to keep borders closured if states want to.