Shadybrook is in icons because of its connection to a couple of the icons.
Tooth Fairy isn’t part of a franchise. The title does not include “Bedtime Stories,” so there’s no expectation for it “continue.”
There’s also no reason to believe Scary Tales is done. Universal has never said Deadly Ever After was the final iteration, and fairy tales is an easy horror trope to regularly revisit. The reason why it’s not back this year is because they just did a Scary Tales “2” years (in 2018) and it has no connection to Carey or the icons.