The authoritarian policy of biased information-giving shows disrespect for people (you can only fool some of the people some of the time) - eg NHS Health Checks, NHS Breast Screening Programme etc. Each time the public learns it is being/has been hoodwinked, trust is eroded and compliance becomes less likely. There is now a growing patient 'movement' which demands that the rhetoric matches the action ie openness. Lying by default is still lying.
Patients should not have to opt out of any scheme. Being able to opt in respects people's autonomy. Having to opt out is Big Brother tactics.
As for the information leaflet - when will those in authority realise that withholding detail on risk/harm/negatives (eg screening, health checks etc) instead of being completely unbiased and open displays contempt, destroys trust - and backfires.