It’s unclear to me if or how the “Vote” moment played into that, but it’s certainly worth pointing out that most of the major networks try to discuss politics from a more neutral or lightly political point of view, specifically when it comes to news coverage.
As for NBC, the FCC has specific rules when it comes to broadcasting about politics.
There are all kinds of complicated specifics about offering equal time, but no one was thinking about celebrities singing about politics when any of those rules were first figured out.