If you think about it, Murali bowled something analogous to left arm wrist spin, as he was a right arm "reverse" wrist spinner, bowling his stock ball into the right hander.
Thing is, as Migara alluded to much earlier in the thread, that style of bowling, and the grip required, makes it really freaking hard to bowl from a control perspective (analogous again more to a wrist than finger spinner). And certainly the supernatural flexibility of wrist and shoulder that Murali possessed, helped him in no small measure.
But Murali to me spun the ball no more than Warne, nor had and greater scope for variation (both had doosra or googly, although doosra is a bit harder to pick).
So to me the style Murali employed means there is scope for success for a left arm wrist spinner too. All it would take is to find an all time talent out of an already diminished pool due to there being less left handers, and lower barrier to entry spin style (orthodox) cannibalizing their talent. Easy enough.