What does any of this have to do with Call of Duty? Waiting has resulted in the regaining of health in the series since Arena, so no, it's not CoD. It predates CoD.
Actually, in past games, or at least in Morrowind, only resting healed you, of course for the purposes of gameplay, it didn't make that much of a difference since you could rest anywhere except in towns even if you did not have a bed (Which, by the way, should return, or alternately, the game should have a portable bedroll or campsite that can be set up to allow you to rest in the wilderness. It's rather hard for me to role-play my character sleeping every day when I can't set up camp and sleep in the wilderness.) Still, it's not like Call of Duty at all, someone who has played both games would know this. The health system of Call of Duty games has the player's health regenerating quickly during combat if you take cover for a bit, in the Elder Scrolls, you have to heal yourself or rest/wait. Or use healing spells or potions.
As far as regenerating health while waiting in Oblivion, I just assume that my character uses a healing spell or something while waiting, after all, since magicka automatically regenerates, of course, I rarely take advantage of this anyway, it just feels weird for my character to pause and take one hour breaks after every fight, not to mention pointless, since it's not that hard to cast healing spells.