>EXP yield is a value every species has, and Audino's just happens to be exceptionally high. Nothing complicated, really.
So like Audino's, Chansey's and Blissey's EXP yield is also a bit higher, so yes I believe they do give a more EXP unless Gamefreak changed it, but I didn't find anything saying they did so I assume they didn't.
Hope I helped!