Considering Abrams also produced the Last Jedi, I would be really surprised if JJ goes in a different direction that is his “original vision”. I guess we’ll see in a year, though, and I guess this debate can never really be resolved until then either.
Yes. Some think Abrams had a grand plan that he had laid out and yet he made changes to TFA in light of what Johnson wanted to do in TLJ. I think he will continue and fully follow all of what we see in TLJ, though some revelations could prove to be false, most will be on the money and remain unchanged. Abrams is used to working on a writing team so I don’t think he was too set on anything he might have had in mind.