could be but the safe bet would be the fan event if it true
I wouldn’t consider the 15th “early April†though. It’s mid-April. Whether this is real or not, the early April event this would be shown off is most likely PAX. They could reveal significant new KH3 info at PAX so the fan event could focus on Union X as intended with just a little tease of KH3.
I think the fan event is much more likely to reveal UX’s connection to KH3 by showing a clip of Sora in Daybreak Town or him meeting Ephemer/Skuld. Something along those lines. I think revealing a new KH3 Disney world there would distract from the event’s focus.
If this rumor is real, which is highly doubtful anyways, I see things playing out like this:
We get the trailer at PAX showing off the Underworld of Olympus which we haven’t yet seen, Sora exploring some new areas of Monstropolis and showing one of the mid bosses there, and finally the Jungle Book reveal.
Then at the UX fan event, we get a trailer comprising footage of all the worlds we’ve seen thus far, a reveal of a new attraction flow or looks at how the old ones have been improved, maybe another summon link reveal (Aladdin hopefully,) and ending with footage of Sora either in Daybreak Town or meeting a Dandelion, if not both.
If the rumor is fake, I hope for the same thing to happen with a different world reveal at PAX.