Even though it was the rubber hose that ruptured and failed, the hose itself can't be replaced individually. The hose is manufactured and bonded permanently onto the whole diverter assembly. Essentially an $8.00 part (being generous) failure turns in to an $80.00 expense for the whole assembly. There are dozens upon dozens of documented reports of the same exact issue happening to others in as little as 2 years time.
According to the manufacturers tech support, the WD19X25278 replacement part is an "updated" version (notice that upgraded isn't the term used). I'm curious to know if folks that have installed the updated WD19X25278 part have had the same failure after a few years? I hope this isn't the case, but we have installed a waterbug monitor under the machine as a precaution.
The replacement was straightforward and the video that AppliancePartsPros.com created is very helpful. My installation varied slightly in that I was able to replace the part without removing the pump motor. Total time spent was around 30 minutes and I wasn't rushing. Very happy with my experience with appliancepartspros.com.