Here's the facts, Batman Triumphant was the original name for B+R, however after that movie the WB suits moved the name onto the fifth movie. This film was going to be darker, with Dick and Barbara shipped off to college and Batman being on his own again. The villians were indeed Scarecrow (Rumoured to be Jeff Goldblum) and Harley Quinn (Rumoured to be Madonna) with a cameo appearance from The Joker whilst Batman was under the influence of fear gas.
The script exists, but it's locked deep inside a WB vault with very few people ever having seen it.
Schumacher wanted to do it straight after B+R, wanting to redeem himself with a darker Batman. Hoever due to poor box office reception to B+R, WB pulled the plug.
Schumacher later came back with the idea of a Y1 film, an idea he'd mooted before he did BF. WB took the idea and shipped it around Hollywood, most notably landing it with Frank Miller and Darren Aranofsky. There script can be read on most internet script sites.
That's the real deal.
And the only thing I can't source is the Madonna rumour. I read that in a British TV magazine just after B+R and it's always stuck with me.
