Yes and no... I'd be very surprised if rD cancels entirely, but wouldn't be surprised to see an advisory like LA Marathon issued - something about keeping social distance while at the expo/in corrals/etc., lots more hand sanitizer stations, maybe at corral entrances + outside porta-potties, volunteers handing over medals instead of putting them over people's heads, that kind of stuff. At a personal level, I'm currently existing in this weird grey area: on the one hand, I am in a semi-high risk category due to chronic health issues, and my 70+ yo mother with health issues lives with me, so I'm being careful with hand washing, some social distancing, etc. - but that's really just my normal most of the year because I live in Tourist Central and am exposed to a gazillion germs everywhere I go. I'm not convinced that WDW is any better or worse than my daily life in that regard. Heck, we've got several people out sick in my office, and I'm listening to a coworker blow their nose right now. It's easy enough to hang out at the back of my corral and keep some distance from coughers/sneezers/spitters. That said... I'm also not sure I want to be packed in cheek-by-jowl in ride lines, or at Oga's.
So tl;dr: I'm not feeling a need to cancel yet, and haven't seen anything to indicate rD is thinking about it, either.