Lots of oil and gas (O&G) construction/services folks looking for work right now in Texas [3], so it's a good time for Tesla to move in. Also, Texas has an abundance of cheap wind energy they can't export due to ERCOT interconnect capacity issues. The SpaceX McGregor engine development and static fire test facility is only 90 minutes north of Austin, and Tesla already has an Autopilot R&D office there for the engineers they hired from AMD. Good pick for the next factory. Maybe a SpaceX HQ relo is in future plans.
[1] https://www.reuters.com/article/us-health-coronavirus-tesla-... (Musk, Texas governor talk about potential Tesla move to Lone Star state)
[2] https://www.teslarati.com/tesla-gigafactory-4-berlin-ground-...
[3] https://www.nytimes.com/2020/04/21/business/energy-environme...