I made a post with some, let's say, slightly risky predictions in the Dauphine thread a few days ago where I basically wrote about Bernal, Pinot and Dumoulin as the favorites, excluding Roglic from that list. While that seems a lot more reasonable now I still really hope Roglic will recover so my original point gets proven anyway (or the whole forum can make fun of my post, but hey, if that's what it takes to make people happy in 2020...)
But yeah, while these three are really looking good to me, if you want a year for surprises at the tour this might be it. There are questionmarks for everyone and I could totally see someone coming out of leftfield to win it. Like, I really don't think Mikel Landa will win the tour, but would I completely rule it out? Don't think so.
If I had to bet though, I'd go for Dumoulin. Still think people are sleeping on him big time.