I'm not sure what has been delaying the Earthspark toys, while the other mainlines are still getting released on time... because the first wave of Earthspark was supposed to have been released at the beginning of November so that they were out in stores as the cartoon was released (in America earlier) so that it helps sell the toys. It is a month later and they have only now just showed up this week in Asia (Taiwan and Singapore).
Missing the release of the cartoon by over a month (in their main market), means that there are less people watching the cartoon while the toys are in stores.
It is why Movie toys are released a couple months before a Movie is released, so that there is full saturation during the peak viewing period.