That depends entirely on the situation. In the case of an active shooter (which is what most of these calls claim) the police are obligated to storm in to save lives. After Columbine these policies were changed because if the police had moved in immediately they would have saved a lot of lives. Instead they did what you suggest as the standard procedure at the time, but that procedure doesn't work with a shooter whose aiming to kill people and doesn't care if they live or die. In that situation the only way to save lives is to storm the building.
There isn't a good solution to these problems that doesn't involve some major changes to the internet that break all anonymity or completely disconnecting the internet from the phone network. Neither is a viable option. Unfortunately SWATting needs to be handled with law enforcement, I guarantee that the number of these incidents will go down dramatically when they start visibly putting these people in jail and extraditing people from overseas that do it. That 14 year old kid might think twice if they know they will get caught. But this would mean the police would need to dedicate investigative money to these crimes, and that's not going to happen as long as drug crime is far more profitable to the police.