I think it is too early to place any definitive bets. Let's wait few days (&games) to see how they look like.
We have already a first "surprise" - Serena Williams is out. I was just checking what are the odds, I haven't found her and I then I saw the news about Harmony Tan. It makes me think to start betting on "others" (8.94) category, as I do not see a clear leader.
You are right in that although there is 1 clear favorite, both on the Men and Women side (just looking at the odds on freebitco.in). The odd for Djokovic dropped already to 1.51, so I will probably not place a bet anymore on him as there is no real value in it. The odd for Swiatek to win is 1.45 which is also way too low for me but as you mention, it can be interesting to bet on the others category (8.3) on the Women side as we might get a surprise over there.