I wasn't around at the time there was any mention of VitaSoy,...

I wasn't around at the time there was any mention of VitaSoy, however I may be able to shed light on what I see as the companies dilemna. Prior to hemp food becoming legal hemp milk was also being produced but like the seeds etc could only be used for cosmetic purposes i.e. you weren't 'sposed to eat/drink it. So assumptions may have been made that when hemp food became legal so would hemp milk made from that seed BUT regulators being obtuse and ill informed decided differently .. go figure..
The current rule is..
"Beverages i.e milk derived from the seed – must not contain more than 0.2mg/kg (0.2ppm or 0.00002%) THC & THCA combined
Due to current legislation Australia is one of the last places on Earth where delicious healthy non-drug Hemp Milk is not allowed to be consumed, so it cannot be purchased in Australia at this time.
Note - until such time as legislation in Australia changes you may only use homemade Hemp Milk for making cosmetic products ."
So by all means make your own hemp milk from your own hemp seeds but by law you'll have to turn it into soap and not drink it