I think that's quite a bit high though. The Phillies' 2019 ratings were a seven-year high (low during that period for obvious reasons) and average viewership was 120,000. In 2010 it was 212,000 (those numbers also lowered due to cord-cutting), third in MLB. That same year the Cardinals and Twins had higher ratings than the Phillies but their average was almost half (121,000 in the Cardinals' case) because of the smaller market.
The A's local audience in 2010 was 30,000!
30 local telecasts probably doesn't even add up to 5 million viewers before cord-cutting.
I don't know the answer to how you reach the more casual and bandwagon fan, or just how low the number is of people who would buy the premium product. Obviously inclusion in cord-cutting is important but if Phillies on Peacock was just free for all Comcast Internet subscribers, that would do it. Assuming Comcast stays on board.