We Icelanders voted in a NON-BINDING referendum, where the first question was "yes / no, I want / do not want the proposals from the public constitutional congress to be used as the basis for a parliamentary referendum for a new constitution". It is then explicitly stated on the voting card that the proposals may change in the process of being worked into a parliamentary referendum for a new constitution - which then again must be approved not once but twice by two separately elected parliaments (i.e. voted through in parliament, parliament dissolved, voted in again, and the referendum approved again there).
Headline is FALSE and misleading.
— edit: that said, I support the establishment of a new constitution, and I like a lot of things in the proposals. There are also some things I do not like. The proposals need work to become fit to be a constitution, that's for sure.