I always felt the Boomer Generation was far too long to have validity, and frequently claim to be a Boomer despite having a decidedly different experience from those born in the late forties and early fifties. I think any generalization of generations is too simple, and yet another way to “other.”
I was born in 1963, don’t consider myself a Boomer, but fit into the category. I wasn’t aware that they split it into two, but just another attempt to label people as different rather than focusing on what we have in common.