That's not wanting to live for ever. That's about maintaining quality of life.
There is no distinction - immortality, if possible, will likely be similar to how we maintain a classic car and will be achieved through a continuous flow of cures and treatments to age related diseases. The idea of longevity escape velocity is that with each extra year you live, enough advancement is made to give you another year.
So living forever would bring you back to the scenario I gave. I cannot imagine a 200-year-old of healthy mind and body refusing treatment because they have decided that reaching 200 is a nice number to end on.