Not at all.
In that specific hate-inciting speech Geert Wilders was calling for fewer Moroccans. And this is primarily directed towards Dutch people with a Moroccan background who've already live in the Netherlands for decades or are second-generation immigrants. There is virtually no immigration from Morocco, in 2015 approximately 1% of the immigrants arriving in The Netherlands was Moroccan [1].
[1] https://www.cbs.nl/nl-nl/publicatie/2016/47/jaarrapport-inte...
Most political parties in The Netherlands have talked about the problems of immigration and integration in The Netherlands at least since Pim Fortuyn 15 years ago. Some parties longer (e.g. Frits Bolkenstein of the VVD, who Geert Wilders worked for). So, it is by no means illegal to talk about current or past immigration policies.
Literally illegal to call for less immigration.