The registration of a model can be 'completed' any moment before the model is placed on the Union market. The recorded information becomes only publicly available from the day that the supplier indicates in a specific field as 'date of placing on the market'. Similarly, both the public and the technical information becomes accessible to Market Surveillance authorities from that same day.
To have the model really published at the scheduled date, all mandatory fields of the registration have to be filled and the model registration marked as 'complete'. Needless to say that the day that the first unit of that model appears anywhere on the EU market, including at customs, the model has to be already publicly accessible. Similarly, scanning the QR will provide a return only from the day of placement on the market.
More info here.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.