Personally no, but i thought we should ask the question since they were in Neanderthal diets. I suspect that they used moss to handle hot rocks and certainly to wipe their ass.
What this makes clear is that eating it is possible but unlikely. As they were eating mostly vegetables it is possible that they fished out chunks to eat with sticks and then used moss to hold the hot food while they ate.
Thus we have ample practical reasons to be handling moss while eating, but no good reason to eat moss. all this would ensure some moss in the mix to be observed now.