
Rio Morales will die (almost certain)
Was looking over some theories online about how in this franchise Miles and Gwen are linked in ways that won't be fully explained until Beyond The Spiderverse releases. Have Also seen some well formulated theories on how their universes will collide based upon imagery in both films (Into and Across).
Miles's statement "we're the same...in the important ways" always stuck out to me when comparing the characters.
Gwen Stacy's mother is Helen Stacy (née Vogel) in the main Marvel Comics continuity (Earth-616). In these comics, Helen dies from cancer early in Gwen's childhood, leaving her to be raised by her father, Captain George Stacy.
In the Spider-Gwen comics (Earth-65), her mother's maiden name is Helen Carmichael. Depending on the universe, her fate shifts; in some Ultimate Comics, she abandons the family, while In The Spider-Verse movies, she is also presumed to have passed away or been absent early on.
Depending upon whether or not this is confirmed Both Gwen and Miles having Mothers who've passed and Father's who are/were police captains seems like an obvious route for the writers to take.
Beyond The Spiderverse is confirmed to be saddest of the trilogy which makes Loss a given, Miles's mother passing would be the unexpected curveball to the audience worrying about Jeff's mortality. Miles's struggle to grieve with the loss of his mother may be partly relieved through his partner (Gwen) having gone through the same thing when she was younger, which has yet to covered in this franchise.
Maybe it's a long shot based upon too many potentials. But just a theory from me.