The German benefits the article talks about are not health insurance (but rather things like welfare for unemployed). It is not considered a benefit, it is considered an insurance. In fact, health insurance laws make (apart from some edge cases) no difference based on nationality or type of residence. If you become a member of a health insurance fund (which you are required to if you work in Germany) you are fully covered from day one including pre-existing conditions. Plans to change that are not even on the horizon.

But you are of course right, it's not possible to simply move to Germany just to receive treatment under health insurance. To become member of a health fund you need to fulfil certain conditions, e.g. by starting employment. This applies even to German citizens moving from abroad.