There is no information at this stage. If you were to GUESS we should get some information around the anime release window.

Idk, Omori has been pretty focused on DanMachi Anime and Wistoria anime. I wouldn't be surprised if we don't get it until beginning of next year.

Vol 20 prologue is revealed, it’s titled “Hero Afterglow”

https://x.com/fujinoomori/status/1830612851184337118?s=46

Omori did this before when he tweeted a chapter title from Vol 19 few months before the volume’s release. Assuming it’s the same amount of time for Vol 20 then it will be released in December.

The title is the exact same title as AR3 Ch9. What happened in that chapter was the final stage of Astrea Familia’s battle against Alfia, their rank ups, and the end of battle against Delphyne. A lot of people ranked up from the final battle in AR. So I’m thinking that Vol 20 prologue will show a lot of people’s rank ups, probably during Denatus which should be happening around this time.

Only found this indirectly through Reddit. Maybe make a formal announcement?

Finally, some volume 20 news