It wouldn't surprise me to see it Mid/Late October.

We should have all info of it though before that time.
I say this because Yoshi has said past few interviews that they want to talk about expansion but holding stuff for Fan Fest.
Meaning I would say NA and EU Fan Fest will prob get information about 2.5 perhaps expansion reveal and the JPN Fan Fest (last one) will be about 2.5 and reveal of expansion (if not at earlier Fan Fest) and more tidbits.

No way will each event have all rehashed info.