Trump also has high education, non-luddite supporters or at the very least supporters that could be brought over to considering investing in a future America that makes itself 'Great' through government spending on infrastructure and science. It could be that Thiel believes he is speaking to these people (some of which might only be Trump supporters in 2016 because they always vote Republican).
My central point is that he's been speaking about both economic and technological stagnation for many years and it is foolish to consider his actions now as completely distinct from this.
I've no idea whether he believes Trump will win or not. I expect that he didn't require it. His donation allowed him to speak at the RNC, and this has no doubt increased his political reach massively.
I was joking when I said liberal newspapers. They are not liberal at all.