In a grammatical sense, "nothing" is the noun in "Nothing lasts forever". We all know that a noun is a person, place, thing, or idea. This whole talk about universes, life and death, cycles, etc. ..... those are all "SOMEthing", not "NOthing".
"Nothing lasts forever". That's great, but the article isn't about nothing. It's about something.
On a different theory, it is described in the beginning AND at the end that the whole article is based on an assumption.