Yes, it is necessary to change your trading method because the market will be upside down.

It's up to you if you would like to change your trading strategies, and monitor the market movement.

You have an option not to change your trading method if you are comfortable with your trading position.

I didn't change my trading method during US election because I do not have a plan to place an order. What I did was I stopped trading for two consecutive days.

I always change my trading method everytime there's an upcoming news. It is not mandatory but it requires to protect my trading account.