Oh no doubt
Batman Triumphant would have probably sucked. Nonetheless, I think the basic idea of a Scarecrow film featuring hallucinations of Nicholson-Joker could have been a nice way to put a bow on that series, if handled right. The 11 year old version of me that was dying to see "Batman 5" would have loved to see that.
But yeah, glad things went the way they did.