Given Cara's past with the rebellion, is it too much of a stretch that she might say, make a cameo in one of Marvel's STAR WARS comics or something like that? Or the "Client" commanding a Star Destroyer or something like that? IG-11 meeting IG-88 etc?
I think while the Mandalorian and young Yoda species background should stick to the show, I wouldn't say that's necesarilly true of the other characters.
While it might seem a bit small universe Disney hasn't been too shy with that aspect. Both Rogue One and Solo took elements from Clone Wars (Saw Gerrera and Maul surviving and becoming a crime lord) as has the Mandalorian. Hera and members of her crew have shown up in the other media-Hera in many of the Marvel comics, and of course the Ghost had a cameo in Rogue One (Some say they've spotted it in one of the ROS trailers).