It wasn't that surprising. Other programs were already discontinued early last year for the same reasons. For example, [Wohnen im Alter]. The funds are simply depleted due to the construction boom.
No one could have guessed that the extremely tight KfW55 deadline would lead to a panic rush and a flood of applications, making it risky for homeowners when parties in government or ministerial responsibility come into power that have no regard for housebuilding – whether with KfW or without. Just think about what you do in the voting booth.