I finished the Josie Riesman book, and I pretty much agree with all of the pros and cons everyone has posted here.
So much of this, of course, we already know. But there is definitely new information sprinkled in too. To have it all in one place definitely paints a fuller picture.
Ending it with 1999, more or less, didn't really bother me. To be honest, I'm not sure what else could really be covered. The author still touches on Trump, the recent sex scandals, etc. It's not as if those details are omitted.
I honestly don't anticipate a follow-up book. If it happens, it will be because of strong sales and nothing else IMO.