The assumption is that using your phone / infotainment system to search for, possibly purchase, and play a new release is an attention-demanding task that takes substantial time. The consensus above is that Spotify's UI, in particular, is poor, and thus requires extra interaction, and thus attention off the road, exacerbating the problem. We know that attending to a phone, even briefly, is mutually exclusive to attending to the road. That alone is an explanatory mechanism for the increase in fatalities.
But then we augment that supposition by the additional effects that new music is also a distraction, albeit much lower grade than operating a phone. It might be a lesser effect, but listening to a song or three is also expected to span longer time than interacting with a phone, so might have substantial cumulative impact.
An additional effect that I have not seen mentioned above is the expectation that the demographic listening to top releases is likely to skew younger, and thus contains drivers with less experience than the population. Less experienced drivers are at far greater risk of accidents of any sort, and are more sensitive to distraction.
And, as a parent of teenagers, the solution is clear to me: do not frelling use your phone when driving, period.
