a) where you noticed information about IGN. In Locus Store > Provider?
This information is correct. IGN maps are already more then week prepared and ready to publish. Unfortunately we are still waiting to confirmation of our solution from IGN owners. If they will send us information till monday, IGN maps will be in mondays version, otherwise you will have to wait another month.
b) GSI maps are in Locus more then year. We just move some maps, that are by default available in list of online maps right after install, to Locus Store. So users who do not care about such maps, do not have them in the list. And yes, GSI maps cover only Japan.
Hope I gave you required answers, otherwise feel free to ask.