Number of walkoff wins in an average mlb season

I just listened to a radio ad in which Budweiser promises to donate $5,000 for each MLB walk off win this season. At the end, they mention a caviat that it is limited to $2.5 million. That would be 500, if my math is right. What’s the point of mentioning that? Isn’t that extremely unlikely?

According to here (The Baseball Analysts: Walking Off), there were 9,887 walkoff wins between 1954 and 2008. So that makes 55 years, making an average of 179.76 walkoff wins (and also losses I suppose) per year. So, there’s that to start out with.

It’s a very easy way to hedge their bet against an unlikely but possible outcome.