I'm the Pinball Map admin for the Champaign Region, which actually encompasses everything in Illinois south of Interstate 80:
The machines in and around Champaign, and to a lesser extent, Central Illinois, are fairly up to date. I rely on others to keep the map updated outside of this area, which is geographically very large.
Sorry, I don't use the Pinside Map very often. There are many, many pinball players not part of Pinside, especially non-collectors/hobbyists, and they tend to use Pinball Map, specifically the mobile app. (They like to play pinball on location, go figure!) Based upon that, they are not really Stern buyers/customers. A lot of Stern customers that have machines in their homes, either choose not to play location pinball, or it simply doesn't exist near them, so...I think Pinside is not the center of the pinball universe, especially for location pinball.
And yeah, Stern personnel read the Pinside Forum all the time...but would Stern ever want to partner with Pinside? Highly unlikely.