The "Brer's" (a couple of them anyway) did, in precious times, appear at the exit/playground area of Splash Mountain.
The thing about these characters is that I'd guess about 98% (maybe more) of WDW guests have never seen them before, and don't relate to them as familiar characters.
Disney refuses to release
Song of the South in any form, so there is no
outside-the-parks reference to them in the experience of most guests.
Yes, I know that there are a few video's floating around from bootleggers or older non-US sources (I own a Japanese Laser Disc, myself) but most guests could not name the characters if they saw them in a police line-up.