The King indeed said: "I am no protocol fetishist" but at the same time he (and we may include the Queen) seems to like a certain royal display when necessary. I think we will see some grand displays of jewels by the Queen. She already surprised by that long not seen enormous sapphire bow brooch (Farewell to Princess Beatrix) or the large "Russian Brooch" (State Visit Chinese President).
There are more signs that King Willem-Alexander actually likes some display when neccessary: - it started with the surprisingly glamorous three days around the Investiture - in January we saw the King in grand tenue, in a state landau and with grand pageantry to a military ceremony - the Investitures by the King so far (new Governor for Aruba, new Commissioner for South Holland, new state secretary for Finances) were all in jacquet (under Beatrix suit-and-tie were okay) - for the fist time in decades the amazing Oranjesael was visible on TV in all its glory, with beautifully laid tables (banquet last week)
That gives good hopes for a re-appearance of the grandest parures (my bet: State Visit to Charles and Camilla!), the use of the now restored King's Barge (my bet: Sail Amsterdam 2015), the use of the Glass State Berline of Willem I (my bet: the 18th birthday of the Princess of Orange)...
But let us not forget: it is NO State Visit indeed, so let us not be disappointed when there are no diadems coming Friday. The new King and Queen are still in their first year and there are so many years to come to dazzle us.