I agree that it may have been bungled, but I think that some of what you said isn't quite right.
The precise text of the constitutional amendment is already set forth. You can read it online. They put it in a physical booklet which was sent to every household in the country. You're right that the messaging was far from perfect, especially near the start, but saying that the "yes" side can't state what they want to change is a bit disingenuous.
Why I think it may have been bungled is that it's the sort of change that needed to be made from a position of political strength, and I'm not sure that Labor were quite there. The "no" side was always going to have an advantage in that it's usually easier to maintain the status quo than it is to change something.
This means that the "yes" proponents have to do a lot more work to argue their case, and when combined with the big problems that Australia is facing (cost of living, housing affordability, etc) I think a lot of folks who would be "in the middle" on the issue are understandably a bit irritated that the government can appear to be putting more work into this than those other issues.
The page I linked isn't authored by the "yes" proponents, it's just an objective description of the change that we're voting on. So it doesn't (and shouldn't) attempt to describe what each side asserts that the outcome of the amendment would be.
For that you can check out the section that each side has in the booklet. There looks to be PDF of it on the AEC site. Outcomes that the "yes" proponents expect for indigeous folks which are listed there include increased life expectancy, improved education, reduced infant mortality.
Those aren't ironclad assurances or guarantees but I don't think we really get those with any legislative changes. Providing some kind of assurance on an outcome would require a much more radical amendment which would likely be fraught with problems
Yeah, I think you're probably right. If the LNP had someone a bit more charismatic than Dutton then I'd be almost certain that you're right. Maybe Labor will get lucky and there'll still be enough lingering resentment against the libs, but they need to be a lot less feckless than the have been so far if they don't want to rely on that.
At the same time it doesn't look like the LNP have learned much from last time either. Really just a shitshow all round at a time when we need some good leadership.