In one embodiment, a device constructs a set of controlled what-if input parameters for evaluating a what-if scenario in a network. The device uses the set of controlled what-if input parameters and state data indicative of a current state of the network as input to a network state model. The network state model predicts values for the state data conditioned on the what-if input parameters. The device predicts a key performance indicator (KPI) in the network by using the predicted values for the state data from the network state model as input to a machine learning-based KPI prediction model. The device initiates a routing change in the network based in part on the predicted KPI.