That refers to the stock solution, not the concentrate right out of the bottle.
You make the stock solution by diluting the concentrate 1 + 3. That was what commercial labs and other high volume users did/do.
The old, original HC-110 - the one formerly made by Eastman Kodak, then made under contract for Eastman Kodak, then made under contract for Kodak Alaris, until Tetenal went bankrupt - i.e, the really viscous stuff - was the one with legendary longevity - so legendary that no longevity information was included in the datasheet.
After Tetenal went bankrupt, and the really complex and expensive mode of manufacturing the really viscous stuff went away, a new version of still concentrated stuff replaced it. That version was designed to perform and did perform in essentially the same way as the old, really viscous stuff.
J-24, describes the care that one needed and still need to take when mixing working strength dilutions direct from concentrate. You will note that there isn't any storage life information on J-24 for the concentrate, and that is because even the less viscous post Tetenal bankruptcy stuff appears to have very long life. It is only the change in the MSDS that gives a clue that the long life is unlikely to be as legendary.
As for Photo Systems not providing new datasheets, they appear to have designed their production to emulate accurately the former performance of the various products they are manufacturing under the Kodak name. Their High Concentrate developer - "Same Great product with a new Name" is probably exactly the same as the less viscous version of HC-110. In fact, they were likely the ones making that HC-110 version for Kodak Alaris, followed by Sino Promise. As a result of the design for emulation approach, they appear to be happy to rely on the datasheets for developers that are still hosted on the Kodak Alaris site.