This was from last month's Vanity Fair coverage.
Vanity Fair: You have the “young Han Solo” story film coming out next year, and Episode IX in 2019. Is there another story film in production or pre-production, beyond the Han Solo one?
Kennedy: Yes. We haven’t identified it yet, but yes. We have a couple of things right now that we’re circling, and we’ll make a decision between the two pretty shortly. It’s probably for 2020, and we will make a decision by June.
I'd say this is yet another announcement we'll probably end up getting at Disney's D23 Expo, in 3 weeks. (Unless a director hiring leaks. Then they might announce it sooner.)