Yes, it is against the license to distribute the actual morphs. However, you can supply the dial settings for the morphs so that people who have them will get the same effect. If you've made a custom morph by taking a head shaped with the DAZ morphs and further modifying it in a modeller then you can distribute that as your custom morph plus the dial settings: in Poser, your'd load the head shape created with the DAZ morphs and the finished morph (DAZ morphs plus your shaping) as a pair of morph targets, set the DAZ-morphs verion to -1 and the combined morph to +1 and export that as a new morph target, which would be just your contributuion: you could then package that as a new injection morph and supply it with the dial settings for the DAZ morphs.

That applies to pretty much all morphs - about the only exception I know of is a set at RuntimeDNA that are sold as a merchant resource. The rule is that if it doesn't explicilty say you can use it as a basis for your own work, for redistribution, then you can't.