It does seem to be a bridge between the two - most of the big celebrity Kates/Cates I can think of were born in the 70s. The latter half of Gen X, I guess?
That said, the Kates I personally know were all Katies once upon a time, so I tend to think of it as the more neutral/"mature" nickname.
edit: and just to stretch this generational sorting even further, Cat/Kat seemed more popular with the Gen Z-ers I went to college with.
This message was edited 8/27/2019, 8:34 AM