Okay, I see you edited out the part I quoted.
Anyway,
Himalayacetis IS an archeocetacean. I'm not sure you can call it a "true whale" - it's really more representative of a transitional. It was found in correlation with marine molluscs, so it was definately at least partly aquatic (hence considering it cetacea), but oxygenation analysis of the dentition indicates a possible fresh-water and marine origin. Also, the dental pattern is closer to earlier Artiodactyls like
Diacodexis than anything else. It's definately a pakicetid, however. Just about 3.5 my older. The divergeance of whales from artiodactyls based on molecular comparisons indicates that the node took place somewhere around 62 mya. That makes
Himalayacetis the oldest whale at about 55-56 mya. It's not a species-to-species transitional, but does add one more link in the land-to-water chain. It IS, without question, a transitional organism. How much time it spent on land vs how much in water is still open. As usual with paleontology, we'll have to wait for more fossils.