Some species of frogs are more tolerant of human disturbance and may be more likely to return to a pond even if their tadpoles have been killed. Other species may be more sensitive to human activity and may avoid the pond entirely if they sense that it is not safe.
The conditions of the pond may also play a role in whether or not frogs return. If the pond is healthy and provides suitable habitat for frogs, such as plenty of vegetation, cover from predators, and a source of food, then frogs may be more likely to return, even if their tadpoles were killed. On the other hand, if the pond is not in good condition, or if it is located in an area with high levels of human disturbance, then frogs may be less likely to return.
The availability of other suitable habitats in the area may also influence whether or not frogs return to a pond. If there are other ponds or wetlands nearby that provide better habitat for frogs, then they may be more likely to move to those locations rather than returning to the pond where their tadpoles were killed.
Overall, it is difficult to say definitively whether or not frogs will return to a koi pond after you have killed their tadpoles. The best way to determine if frogs will return is to monitor the pond over time and see if you notice any frog activity. If you do not see any frogs, you may want to consider making some changes to the pond to make it more attractive to frogs, such as adding vegetation, cover from predators, or a source of food.