I found some raws. Turns out two chapters have been released/leaked. I can't really tell, but here's some info I could pick up from them:
Spoiler for Chapters 1+2:
- Fairy Tail gets a new member named Touka, who is obsessed with Natsu and calls him "my sweet darling". There are two others, a strength-obsessed douchebag and some wimpy kid, but Laxus scares them both away.
- The 100-Year Quest has something to do with Team Natsu visiting the oldest wizard guild in history, Magia Dragon, on a continent north of Ishgal and Alakitasia called Girtina/Giltina.
- The client is the "first master" of Magia Dragon, named Elfseria. He appears to be a dragon at first, but Natsu and Wendy see right through his disguise, revealing him to be an old human dude who's somehow been around for centuries. He also likes to teleport around the room including (where else) between Lucy's boobs.
- Juvia and Touka become rivals for some reason, even though they love completely different people; I'm sure there's an explanation in there. Interestingly, Touka lists Briar (that Avatar lady) as one of the people who already like Gray, which makes Gajeel real suspicious of her.
- There's talk between Lucy and Virgo, and Aquarius's key is pictured, but the scans cut off there. I don't think they were finished.
EDIT: The images have updated with a reveal on what the job entails: