Do you believe that Celestia's immortality will meet an untimely end?

[MLP Moth 224]

No. If the show were pointed to older teens or young adults Celestia might give up her immortality to save someponys life or for Equestrias survival against a very destructive opponent. that would be cool and very heartbreaking at the time.

[Thrashy 2,800]

I've always made a differentiation between immortality and invincibility, myself. My headcanon dictates that while Celestia will never die of old age, starvation, sickness, or anything else that can be attributed to natural causes, she could still be slain by a powerful enough adversary. This theory is cool to me because it adds a bit more dramatic weight to Canterlot Wedding, as there'd have been a very real chance that Chrystalis could've killed her if she'd wanted to.

[Zoraxe 546]

What if she just retires then? Like she has only 200 years left to live or something and she leaves Twilight in charge and retires to a tropical island to lay in the sun and drink margaritas? Or maybe just going to Canterlot retirement village and playing shuffleboard with Luna.

 

[spacestorm 183]

I think that Celestia, like rest of alicorns have some mission or destiny that she must fulfill before she can go away to maybe some kind of heaven or become a spiritual form.

She is only a princess - there probably is a queen who really can be considered as a godess.

Controlling the sun is not her main mission - I think she need to stabilize it presumably due its broken cycle by discord.

I think that her destinity was to find Twilight and now she must help her with being princess - becoming alicorn is not enough.

So she is immortal as long as its needs to be.

[RrVPfX9cPtw59FpC 1,304]

Well, although I might not agree with her being immortal, let's say she is. When she gave Twilight wings, that might have meant that she had a predecessor now, and didn't need to live forever any longer. That's just my belief.