They probably would have gotten to it on their own. But I think TPM Reader NR is right about the trajectory here.
There’s an added component to your piece today on the media’s call for Harris to do interviews and put forward policies — the demand was a Republican demand first, and the media picked it up. Reporters didn’t come to this in some collective epiphany that they wanted more from the Harris campaign, but instead heard Trump and Vance and their surrogates claiming Harrs was too weak or unprepared or stupid to handle a presser. It is, once again, the media being led around by the right wing on what’s important and not important.