Yes it was the successor
Louis
You are correct, a completely all new machine, launched alongside the simpler and de-featured Hoover Automatic, which had no powder dispenser (its on the top, left hand rear on this machine) rotary programme selector/two rocker switches and no stainles steel wash drum. Paul can correct me, but I believe the first models were cold fill only.
Both were revised fairly early on, the Keymatic getting a powder dispenser drawer so it could (in theory) go under a worktop and the Automatic programme selector being revised to a single "Pull For On", shall I say conventional, rotary dial. I think at the time the KM became hot and cold fill, not sure but I suspect the Automatic remained cold fill
Al