All of this applies to the TouchWiz rom build the phone was on prior to installing an AOSP variant.
If ever on a TouchWiz KitKat build prior to flashing an AOSP rom, you cannot go back to jellybean.
If never on a TouchWiz KitKat build prior to flashing an AOSP rom, then you can flash TouchWiz jellybean.
In sum, yes. Everything indexes to the last TouchWiz build you were on as to whether you can flash jellybean now.
As noted, once the phone has upgraded to TouchWiz KitKat, no combination of steps of which I'm aware will ever allow you to go back to jellybean.
Sent from my SM-N900P using Tapatalk