This is true and is an example of an inconvenient truth.
But it's also important to note that Mamdani didnt cancel the project because it was the predecessor. That's often all too common in political leadership positions and is why it can be so bloody impossible to get long term benefits/plans to be executed.
Spite, ego, politicking all makes for terrible leadership but it's often what seems to be celebrated. Good on Mamdani for seeing something worth having and not needing to be the author of it just for optics