For what it's worth, I would like to be proven wrong with Episode IX, but as of right now I feel J.J. Abrams is getting a lot of praise for his set-up in TFA and how Rian Johnson just took those ideas and ripped them up, without there actually ever being the promise that he would answer those.
Don't get me wrong, I love TFA and I admire J.J. for being able to recapture the spirit of Star Wars after the Prequels at times seemed to have lost it and just give us a awesome ride (but that's never been his problem, the Star Trek reboots I love because he exactly brings to the screen what he brought for TFA; epic sci-fi adventure that was fast-paced and thrilling).
It's just that I feel some fans are taking that idea a bit too far; like saying J.J. Abrams doesn't approve of TLJ's changes seems weird seeing as Abrams was part of the process (executive producer) to TLJ and could've chimed in if he wanted to change things - or for instance have said not wanting to do Episode IX because of him being displeased with the changes Rian made (probably under the same 'creative differences' reason that Lord and Miller and Kathleen Kennedy used) seeing as they prevented him from doing his 'original' solutions.
But still, forgetting that fact, I feel people are still forgetting that J.J. Abrams lives for the mystery box but has - so far - not really proven he can execute it all that well (depending on how you look at it).
He seems to be more interested in how to make people ask questions and keep them interested, then actually answering those questions.
He uses mystery as a substitute at times for creating tension or interest, but he doesn't seem interested in revealing what the mystery actually is (or if he does, it's really anticlimactic/underwhelming).
He did it in Lost, with Super 8 and he did it with Cloverfield and to a degree with Felicity and Alias; he will throw things and see what sticks, but won't have any long-term plan.
Now for what it's worth, I will give him the benefit of the doubt that it was Disney who wanted to have a Star Wars movie by 2015 and that J.J. was courageous enough to step up to the mighty task and had to quickly come up with a plot to a sequel movie that was going to please as many people as possible and he succeeded in that.
But to think that he had some grand plan laid out with answers to who Rey's parents were, who Snoke was, why Luke went into hiding, etc. etc. I think is jumping to conclusions.
Mean, until last summer, J.J. Abrams would've been mostly done with Star Wars as it was Colin Trevorrow to direct Episode IX (which trust me, I am happy J.J. got the job, cause he seems way better equipped for a blockbuster than Colin, Jurassic World just didn't cut it for me).
What I think Abrams did is make a mystery to bring people back into Star Wars and get them more invested in the sequel trilogy, but never intending to actually answer any of the enigmas posed, as that would be the job for Rian Johnson and Colin Trevorrow.
Now who knows, seeing as he's back for IX it could be he will prove me wrong, but as of right now I feel that we're not going to get any more closure than we got from Rian in TLJ.
Mean, that's why I want to repeat that I don't dislike J.J. Abrams and that he doesn't execute the mystery box well in a certain way, but really well in another; sure he uses it as a device to an insane degree that it almost becomes a joke (seeing as he just uses the mystery to create interest/hype, but doesn't ever make the mystery worth your investment), but he is a great director nonetheless.
Cause that's how I see Abrams; someone who's not interested in the destination, but in the journey itself. And how does he get the journey started? By introducing a mystery that puts our characters on a journey, but it seems Abrams never cared for what lies at the end of the rainbow; he wants to show the characters interacting while getting there - which like said, I do think is an interesting way of storytelling; for example Super 8 despite the mystery being forgettable, has great acting from the kid actors and makes it worthwhile because of the characters they play.
So I do have high hopes for IX that we will get a great movie, but I highly doubt that J.J. Abrams has (or even had before Rian made TLJ the way he did) any plans to wrap things up nicely in a bow; I think he's more interested in seeing Rey, Finn, Poe and the others interact with each other and against Kylo, then actually telling us who Snoke was.