That one is kind of a bit hard to predict! I'm a fan of any method (PLA & SwSh) that increases the shiny chance the more something is battled so I would like to see that back :)
I just hope you can see a shiny in the overworld like in Legends.
What if egg hatching happened at the daycare and you could see them hatch in overworld? you could see them hatch into shinies.