MP4 save stations

I've seen some people and some articles mention that save stations will not restore health or ammo to full depending on the difficulty. I find this as a good choice which will make pickups more relevant as compared to other entries on Prime....however, is it true? And if yes, does this apply on normal and hard difficulty or only hard?

I ask because I can't get this from a reliable source like an article that show where Nintendo put this info. I think I also remember someone mentioning this on the previews but I don't remember who.