Absolute rubbish - do you have a link to that document that you found ?
I very much doubt the Government would remain the Government for very long if the started using terms like "racist white people".
We do not use the term 'demiliterized' we use 'deactivated' and a deactivated weapon CANNOT be un-deactivated.
The law that came into effect in December 2019 was to actually formalise the purchase / sale / registration of Deactivated firearms - NOT to make ownership illegal.
It sounds as if you have been reading some weird underground tabloid news-sheet.
You may find the attached of interest showing part of what needs to be done to de-activate a firearm.