I agree with most of the article, as long as there is an opt out.

However, for organ donation where I feel direct rather than implied consent is required, options such as boxes for direct consent to override the wishes of relatives is required, as many potential donations are stopped because direct consent of the next of kin cannot be obtained in time.

There will be resistance: Companies profit from inappropriate defaults.
Defaulting to benefit consumers is like running a decent public transport system: beneficial to the masses, but detrimental to special interests.
In case you haven't noticed, special interests have "governed" this country for the last decade or so!
Otherwise an excellent idea.