It's not about that. Nobody tuned in to see it, just like nobody bought a ticket to see him throw out the first pitch. But like the game itself the TV broadcast is an entertainment product. It has multiple elements beyond just the action on the field. Plus those interviews (whether with Questlove or J-Roll) then become shareable content on the NBC Philly site, and social media. And then Questlove probably mentions his day at the ballpark on that other show, which is publicity.
As a partner in the broadcast network the Phillies are basically a media company. We all just want to watch baseball but that ship sailed long ago. Major league games are like minor league games now, and TV broadcasts are variety shows. If all they had to sell was baseball to baseball fans that Comcast money wouldn't be there (at the same level).
This won't be as big a problem on a Thursday in June. But then it will resurface in the playoffs when the national networks get gimmicky.
Chase is doing the studio analyst thing, not joining the on-air team.