They are two different things.
A life interest is an interest in possession trust for a lifetime.
A right of residence can either be an exclusive right or not. An exclusive right of residence allows one to exclude anyone else from the house.
They have different values for tax treatment.
Yes one can give up a right of residence or a life interest, giving these up also has tax implications. But if you have a life interest or a right of residence, and you go into care and you do not voluntarily give up that right, whether because you don't want to, or you lack capacity to, then you still have it. It doesnt die through lack of use.