The importance of Gigafactory 3 cannot be understated. Tesla needs to get Giga3 up and running as fast as humanly possible. There are two reasons for this:
1) Chinese tariffs (it's obvious)
2) Trump is looking to start an auto war with the EU. He is supposed to have made his decision by 5/18. See below.
EU trade chief sees possible extension to May 18 deadline for U.S. car tariffs: newspaper - Reuters
This trade war can be a blessing in disguise as China has not put tariffs on Tesla cars, and this further derisks Trump starting a fight with the Europeans.
We need a China gigafactory, as once Trump patches things up with China, the EU is next. And we need to be able to ship cars from Giga3 to Europe.