Sorry, you must have missed many missing person cases. Police and family are very reluctant to mention the possibility of self harm early in a missing person case for a couple of very good reasons. First, the person may still be alive and they don't want to do anything to make it more difficult for them to return. Second, public assistance typically drops off at the mention. Just because they didn't mention it doesn't mean it wasn't on their list of possibilities. There were a lot of red flags.
I suspect the police have a lot of information including the welfare details, that Willow was tied up to the bench and eventually pulled out of it or chewed through the leash (wonder why we didn't hear about the leash), that her phone tracked its usual path and her fitbit was attempting to connect through bluetooth until she walked away from the phone. All IMO.