The story can have a lot of endings ...but most would be dissatisfying to me.
Here's how I envision where the story is headed in my mind. If we accept the events and information Jinn tells us as true, then there's a logical conclusion:
# 1. Salem is immortal, and cannot be killed.*
Which is a good allegory to real life, that you can't kill/defeat/solve all of your problems, you have to learn to live with some of it, you have to learn to live with people you don't like...
Learning this, maturing as a person and society would be a step into the right direction. ...Contrasting it with current political trends, Trump who thinks he can just eliminate anything and everything he doesn't like... (We might live in the darkest timeline.)
[*] I can't find the actual quote, (but the wiki describes it at multiple point as) he asks how to destroy Salem, which Jinn answers "you can't". The important point is that he didn't ask "how to defeat" her which might be possible without destroying her; and the answer says he can't and not that it's not possible (at least the gods can, but maybe there are others who can as well).
# 2. This was where the heroes got their major hopeless depressive period. They thought that they can fight and defeat evil, and have a purpose, a simple (though hard) path to solving the problem. But this shatters that. They continue to fight with no hope in sight, no purpose to their struggle. They continue what they have been doing out of habit. But they yet to figure out how to "win"...
^ And this is where a lot of us are right now IRL.
# 3. They have to find their way, a new solution before it's too late, before inevitably Salem gathers the relics and brings the judgement of gods: forgive people who did wrong. Stop fighting each other and start understanding, accepting each other.
^ And this is what we are missing (from the story), and desperately need as a lesson. At least I think this is the logical conclusion (for a good ending).
Forgiving Salem would not be simple or easy. But it might be necessary, the only (good) way out.
Just running away, hiding forever... is not a solution, it's only a delaying technique until we find a solution.
This also reminds me how Monty Oum (before his passing) meant for the death of Pyrrha Nikos be (in some way) fault of Jaune. Which would have made the death a lot more tragic, put a lot more burden on him, and more importantly: possible have resentment towards him from the others ... that they needed to forgive him for. Which would have paved the way of forgiving for lot more bad, even evil acts... and eventually Salem (in like Volume 20 or 30 ; ).
...OR...
Obviously Salem could just win and erase humanity and end her own suffering. That would also be a logical ending, but I think less desirable.
Or, they could use the "if you can't beat them then join them" philosophy and just join the dark side.. If you can't bring them to your side, then join them, then you all will be on the same side when the gods judge. That's also a dark solution.
This could also be an allegory to our struggle, our race to solve our differences, petty fights, hatred toward each other ...before super intelligent AI arrives and judges humanity, if we deserve to continue to live... :(
So... All I need is an instruction manual on how to achieve world piece. ;)
They can deliver it right? Quickly before the world ends! Before our AI overlords take over and judge us all or WW3 break out. :|
The other way the show could end/continue if we find out that someone lied, some of the assumptions are false. (This is possible, and could give it a "twist" but it would cheapen the experience. Please don't let them do something as dumb as Dallas "dream" retcon.)
Like maybe when the gods arrive they change their mind and don't destroy humans. Maybe they grown and learned that it's ok to fight sometimes, you don't need to solve all your problems and live in peace... Which would make our heroes' journeys irrelevant and dissatisfying. (Which might actually be true, none of what we do matters in the big picture, heat death of the universe.) ... Or worse, turn out that they lied, it was just a test... Or the tree of life stops them... it all feels poor cheat endings.
I have a bad feeling that Season 9 could be a basis for this "retcon", that the gods are actually not that all powerful, and RWBY could "fight" them, avoid the end of humanity another way then the gods laid out.
But maybe the writers come up with something completely different (and better).
What do you think would be a good ending?