In reading this thread, and thinking about it, I think “good for Tulane”.
I also do not know what prompted to Tulane to take this step. Like some others who have commented, I am figuring that they must have had some good reason to do this.
I am not a fan of ED. However it is supposed to be a tradeoff. The student needs to make up their mind early and commit, without even knowing whether they get in. In return they might get an improved chance to be admitted. If they want the university to live up to the university’s end of ED, then the student needs to live up to their end.
I think that Tulane’s move here helps to bring fairness back for the students who choose not to apply ED.