There’s no need to even think about the erased timeline.
Just imagine Zeno was on a planet,
then he destroys that planet, and now he’s floating in space.
After that, Goku shows up and talks to him.
When a planet is destroyed all the matter that made up its surface and atmosphere is scattered into space.
In the vacuum of space, there’s no air, no pressure, and temperatures can reach near absolute zero
Any living being suddenly exposed to that environment without protection would face vacuum exposure, lack of oxygen, intense radiation, and extreme temperature swings.
Characters like Goku surviving in such situations for even a few seconds implies extremely high durability.