To make Kiyoko more distinct and to follow the role.
Kiyoko already has the distinction of being able to give birth every five days, as opposed to every 270 (or however long the other kitsune pregnancies take).
If Kiyoko needs to stand out, I’d rather it be organically, by giving her content that focuses on her role as den mother, and that draws attention to just how many kids she’s having, how she’s raising them, etc. IDK, after what happened with Kinu, you might be able to participate a little more. Or maybe give her more pregnancy-specific content—as is I think she only has the double belly-job with Miko.
I also think lore goes out the window when you can have hundreds of children all under the care of one person in the nursery of a small border-town. There’s just a slight inconsistency problem. For Kohaku in particular, she says you should wait until your kid is weaned before you have another, but realistically you could spend however many years that takes in-game, and then what would be stopping you? The code, not the lore.