I mean if you want to get real crazy speculative, my personal philosophy assumes that the universe is on a loop and at some point in every loop, some version of that universes intelligent system figures out how to build the Daemon and that kicks off the next loop.
Something like proton decay resulting in the permanent non-existence of baryonic matter is unimaginable timeframes, but the Earth will lose all of its carbon dioxide, and hence all eurkaryotic life, within around 1.3 billion years of now. So that's the longest any multicellular creature inhabiting the ocean can still be around, unless far future tool-users figure out how to migrate to a new planet with chemically similar oceans and give them an assist by taking some.
I would argue that by invoking the concept of immortality, you have therefore invoked the “unimaginable timeframe” of infinity to the conversation from the outset.
so it’s not like it was ever not part of the conversation
The better word to avoid confusion here is amortal, meaning it would not die of old age. True immortality is much harder, as accidents would still pose a risk in the long term. Like the janitor pulling the plug on the livable space you set up for the jellyfish, without warning.
Entropy guarantees that every system will eventually disintegrate