I was able to see our preliminary boarding pass this morning. It says we are to embark at Passenger Terminal Amsterdam, but no reference to Waterland or a transfer.
Voyage No/Name: Y248A / 21-DAY VOYAGE OF THE MIDNIGHT SUN & VIKING SAGAS Embark Port/Pier: Amsterdam, The Netherlands / PASSENGER TERMINAL AMSTERDAM
EDIT - as I read further, it also states:
PIER INFORMATION
Please refer to your boarding pass page for the specific pier name.
Passenger Terminal Amsterdam
Piet Heinkade 27
or
VCK Waterland Terminal B.V.
Elbaweg 10, 1044 AD Amsterdam, Netherlands