David Reich, one of the principal authors of the study in question, wrote a book a few years back titled "Who We Are and How We Got Here", which I quite liked (https://www.goodreads.com/review/show/2605841954). It predates some of this research, obviously, but it does have a chapter on the Indo-European origin question, along with chapters on a lot of other interesting paleo-DNA research.
He was on the Dwarkesh podcast last August to provide some lay person friendly synopsis and updates to “Who We Are.” Worth listening to even if you have read the book (in my mind at least).
Warning, link has an auto play when I opened it (but don’t let that minor obnoxiousness dissuade you from listening).
