There's a bit of a hit-or-miss situation for them, from what I can tell. I recently spent some time trying to figure out which MLB The Show titles worked for emulation, and somehow after the 2010 entry, all of the remaining PS3 ones have a notorious noticeable bug where the middle (from right behind the pitcher going all the way down to the center field fence) the field is covered with random fans or other "debris", for lack of a better world. As far as I can tell, it's been known for years (I think it's an instance of the general problem of Z-fighting), but either no one knows the exact solution, or the people working on the emulators have so many other things to work on that it's not a priority.

On the other hand, the fact that people have spent enough time to write down which entries have this bug and which don't (and potentially even which stadiums have it and don't in the entries that do have the bug, since it's apparently not consistent across them) does lead credence to the idea that the library is pretty widely distributed.