Does it REALLY matter whether Logan can die of old age or not? 😬. Why is it such a debate? There is really not much evidence to prove either side.
On the one hand, it's been stated that he has DECELERATED aging.
On the other, he can come back from death a, seemingly, unlimited number of times.
The two, obviously, conflict with one another. Perhaps each time he dies, he comes back in his 'prime'. Perhaps (as I believe Srank hypothesized) the first time he died and came back, he stopped aging.
Either way, it doesn't really matter, does it? Whether Wolverine will live to 1000 or not? 😬.
Also, it has NOT been stated that Wolverine's been immortal since 1991. It was hinted that he could POSSIBLY immortal since 1991, the same way the Storm has been HINTED at being an Omega mutant. She's not. 🙂.
I'm totally cool with Wolverine's new immortality. It actually makes me like the character more, because now there is an excuse for his ridiculous healing feats. Before it just seemed like PIS. Now there is a canonical reason.