Can "no longer" refer to a finite, forseeable time period, or does it indicate a long-term finality? For example, if someone says, in anticipation of a large meal, "I shall no longer be hungry," does that imply that they will never be hungry again?
Examples based around "being hungry" are problematic. In one way of looking at it, we might say a person who never experiences "being hungry" is lucky - if what we mean is he will always have enough to eat.
But there are plenty of people whose very lives are threatened by the fact that they don't experience the natural feeling of "being hungry" and/or lose their sense of taste. Lamisil/Terbafine, for example, can have these effects (sometimes permanently, and it's much worse than most people imagine). It's obviously hard to eat enough if you never feel hungry, and eating itself has become truly revolting. So let's look at OP's construction with something a bit less awkward...
Becks: "If I give away all my money I will no longer be rich"
Posh: "Don't worry pet. With your $50M salary from Paris Saint-Germain we won't be poor for long"
In short, it's not that "no longer" particularly implies anything about the future. All it means is that something that was true will stop being true. Whether it becomes true again in the future depends entirely on what kind of thing it is, and the uncertainties of how the future plays out.