Will all meshes include a UV map?
Will I get a UV map for all meshes?
Simple answer is yes. However, depending on the mesh, it might have more than 1 texture face. If this happens, you would have 1 UV map for each texture face. With the way meshes work in Second Life, you can have up to 8 texture faces per mesh. So you might end up with 8 UV maps that are needed in the packages though to ensure you have everything you need.