>>4470631
Eh I'm 60/40 on it.
>game shows Cai running around in the field which you also saw with Byleth, Shez and Alear which would mean he's supposed to be the self-insert; it was months after 3H's reveal before female Byleth was revealed
>in Leda's part of the trailer Cai is a green unit rather than a player controlled blue unit or a red unit
>Theodora, Dietrich and Leda all have access to storage in their command menu, traditionally only given to MCs(e.g. in Awakening Chrom has the convoy command rather than Robin), and all four of them have distinct insignias in their UI
>adult Sothis scene is clearly from someone's POV

If a proper avatar character isn't revealed and there's no route choice, I'm guessing it's probably something like FE2/SS/RD with multiple MCs in play and perspective jumping around.
That said no avatar doesn't mean no yuri. If I can find wives for Theodora and Leda or even marry them to each other somehow because we need that kind of high intensity couple in this franchise, I'd say we're in business.