May I be so presumptious to say that there will be some type of an instrument of abdication ceremony by Queen Margrethe transferring her authority to the new king, Frederik. This would be followed by the usual pronouncement of the new monarch by the the prime minister and a speech by the said monarch and expressing his motto to define his reign, e.g.,Queen Margrethe's motto:
"Guds hjælp, folkets
kærlighed, Danmarks styrke."
https://en.wikipedia.org/wiki/Royal_mottos_of_Danish_monarchs