I'm surprised Cathay of all companies have chosen to be the first one to roll this dice
When the negative publicity comes - which it will, because we'll make sure that it will - their carefully built up image as one of the safest airlines will be seriously jeopardized.
If they lose even a few thousand nervous pax per year across the network as a consequence, then all of the alleged cost savings will be gone, and they'll have nothing to show for it but a damaged reputation.
If / when an incident happens while single pilot, they risk getting their image absolutely trashed on the same scale that happened to Malaysian, or worse
Very little to gain and everything to lose IMO