Long answer short, yes. They aren't gonna resolve the Eldrazi threat in this block.
All story teases up to this point, whether from Maro or in UC, have said something along the lines of "at least one of the titans remains on Zendikar", implying that the others may have left, while sidestepping confirming it.
Honestly, they hate Dominaria so much these days that I wouldn't be shocked to hear they sent Emrakul there and just wiped it out of existence. Would be real sad, but would also help clean up an element they're happier brushing aside as of late (Liliana's origin story notwithstanding).
But really, finishing off the Eldrazi, or containing them again will be a huge deal, and likely will be something they build toward. I feel like we're entering "Act 2" of the Eldrazi saga, where things become their darkest and all hope seems lost. Should go for a couple of sets with that, anyway, then go into "Act 3" where they find a way to defeat the threat and move on to the next story beat.
Oddly, I'm wondering what happens if an Eldrazi ends up on New Phyrexia. Perhaps taming an Eldrazi and having the Phyrexians usie it to planeswalk would be a good "Things have gone from bad to worse" moment in the story for our heroes.
And now I'm just rambling, but I'm still holding out hope Nicol Bolas' big master plan is one of those "Done for the good of the multiverse" type situations and he ends up as the character with the best path to victory against all these evils in the end. I don't actually think that's what's going to happen -- they seem to love him being positioned as a pure evil if mysterious figure -- but I can hope.