You're right that it will have to be in 2027. JP Fanfest is at the end of the year (delayed by 2 months for some reason). They will not do this fanfest after 8.0 releases because the entire point of it is to reveal information about 8.0.

After the JP fanfest, we get a live letter and the job actions trailer.

We also get a media tour, which takes some weeks while they travel around the world hosting media events.

All that is unlikely to happen literally on Christmas, so it will likely have to be delayed into early 2027.

If it's in early 2027, why not delay it until their favorite release period of June/July/August, the month most expansions have released?