I was curious about trying to unlock Illusion: Void Edge. It looks like to be able to get to the point of being able to attempt the scenarios, you’ve got to complete much if not all of BFA ?
I unlocked it back when it was current, so can’t attest to the time it would take today, but this wowhead article (linked below) looks like it has a nice condensed list of requirements for getting to the visions questline. You only need friendly with each faction to progress (If Alliance, Drustvar rep isn’t awarded until futher into the questline, though).
You won’t need to do all of BFA, though, just the initial questlines from each major patch to get to the next one. The visions questline itself was pretty lengthy, and you will need to farm currency from assaults to do the visions. If you are doing it at max level, it will be substantially faster even though there are a lot of quests to get through.
The Dragonflight and TWW introductory quests may phase you from receiving some of the Heart of Azeroth quests, so be sure those are done on the chosen character, also.