Prince Constantijn and Princess Laurentien are not at Prinsjesdag this year:
"Prince Constantijn and his wife, princess Laurentien, will not attend the Speech to the Throne of their brother (in-law), King Willem-Alexander in September. Covid-19 is the reason behind this decision, made by the president of the States General and the Senate, Jan Anthonie Bruijn. Guests – members of the Senate and the House of Representatives are not allowed to bring a guest, as they usually do. For Queen Máxima has been made an exception. King Willem-Alexander told: ‘she is playing a part in the constitutional frame, so she will be joining.’ Due to the pandemic, the location has been changed to the Great or St. James’ Church in The Hague, no carriage rides will be held, neither will the royal family wave from the balcony of Noordeinde Palace."
https://royalinsider.nl/uniek-constantijn-en-laurentien-dit-jaar-niet-op-prinsjesdag/
"Prince Constantijn and his wife, princess Laurentien, will not attend the Speech to the Throne of their brother (in-law), King Willem-Alexander in September. Covid-19 is the reason behind this decision, made by the president of the States General and the Senate, Jan Anthonie Bruijn. Guests – members of the Senate and the House of Representatives are not allowed to bring a guest, as they usually do. For Queen Máxima has been made an exception. King Willem-Alexander told: ‘she is playing a part in the constitutional frame, so she will be joining.’ Due to the pandemic, the location has been changed to the Great or St. James’ Church in The Hague, no carriage rides will be held, neither will the royal family wave from the balcony of Noordeinde Palace."
https://royalinsider.nl/uniek-constantijn-en-laurentien-dit-jaar-niet-op-prinsjesdag/