They came out in c97 didn't they, so it's fairly period-correct on a 96 bike? I remember seeing a test of the 98 Muni Mula in MBUK and they said the only difference from 97 was fitting a riser bar and it totally changed the character of the bike from being a race bike into a hooligan bike.
I've never understood it myself - why do people find they give more control, is it the height or the width? Surely you can tune the height with the right frame, stem stackers and stem, and if it's the width, there's plenty of 60cm flat bars, or I think the Titec Flat Tracker is 64cm. So why riser bars?
BITD, I always thought it was just that people prefered the look of them.