That is really weird, this isn't a Mars Colonial Trasnsporter, it's a factory. It's been done 1000 times before and there's many companies that specialize in that sort of construction. Heck, there's a division of my company that builds nothing but Costco's.
It must be an allusion to the issue being political in nature. "Just because we've broken ground doesn't mean we're making batteries yet."
There are a lot of folk who want to see Tesla fail and do not want o see the Giga factories in production...many of these folks have influence over lawmakers, etc. this is a smart move by Elon just incase they choose one location then some new politicians come in influenced by big Oil money and try to shut it down...then there is still a 2nd location.