Considering the July 1st teaser date, my best guess would be something at Anime Expo. Looking through the July 1st schedule, there's a number of major companies teasing new projects. This is Studio Trigger, Bandai Namco, Mappa, and Wayforward. If Mori is getting attached to something, then I'd look at the From Japan to the World panel or the Toho Animation panel. Honestly I don't know if it was nervousness talking when Mori said "literally everyone" heard of series she's collabing with, but these seem to be the companies that have IPs that might fit that description by Mori's standards I'd wager. The fact that the announcement will be coming early in the morning NA time will mean it's definitely a Japanese company, but that doesn't exactly narrow it down lmao.
