The labor union question came up on Twitter when he announced this, and this was his most recent response on Twitter, in case you're interested. I admittedly have not researched the labor union question much, so I can't really comment on it.
"I’ve never stopped a union vote nor removed a union. UAW abandoned this factory. Tesla arrived & gave people back their jobs. They haven’t forgotten UAW betrayed them. That’s why UAW can’t even get people to attend a free BBQ, let alone enough sigs for a vote."