I don't believe that they're integrated at all into the game, at least in the sense that it's a real-time representation of the world delivered to us via the web. I don't think I've ever heard them talk about the D&SS map in that way. What we see is what exists at the time domains are selected. What happens in the months and years to follow will be up to us to document.
With respect to discovery, exploration of the world will always involve seeing/experiencing things at the street level. What we have on the web is a crude satellite view of it, and that doesn't tell us much other than the general geography of the land. The starting continent is also only ~30% of the world, and we know nothing at all about the remaining ~70% of it.
Generally speaking, there are two things that compete with one another here: the ability to govern lands and the desire to discover the unknown.
To choose our places in the world and to govern effectively as stewards of Elyria, the starting continent has to be relatively well known. People have lived there and families have ruled for many generations, so it makes sense that we'd know our surroundings. At least, all the civilized parts. The nobility are even supposed to get a detailed map of their domains, which again is something you'd expect for those who have the responsibility of ruling.
But there are other things players will know nothing about, like dungeons, caves, mines, ruins, and all manner of resources waiting to be discovered, including minerals, animals and plant life. And if some of their concept art is any indication, probably even monster lairs. There are also supposed to be islands off the coast where exploration is possible, if not necessary.
And if that's not enough to assuage your concerns about having enough to discover, none of the maps we have detail what exists in each of the settlements, many of which are enormous capital sized cities. Just discovering, documenting and maintaining that will be a tremendous undertaking.
Remember too that the world is not frozen in time. It will change and evolve as the game is played and dynasties rise and fall. We don't need to be blindfolded and completely ignorant of where we live to make it exciting to take our first steps into the world.