Songshan airport will be closed, there’s a tidal wave of money to be made out of it.besides, Taoyuan certainly does have the capacity to handle all flights when upgraded (unlike some other capital cities).
The airport MRT will be around 35 mins into the city.
The narita express in Tokyo takes over an hour!
Taoyuan airport will also be connected to the high speed rail in Taoyuan and there’s plenty of rezoned land around that area. It’s going to happen.
If the plane crashed into a building probably would be shut faster.