why not rake the moss off then the soil will be ok. if you need extra depth of soil then I would still rmove the moss first. if not it will rot down.

dig the moss covered soil over, removing any excessive clumps of moss as you go - moss likes to grow on uncultivated, undisturbed soil which is moist most of the time, so digging it over spring and autumn will help enormously. If you just put new topsoil over it, and the area is then left, moss will grow on that too.