No. I did not think that your response was discourteous.
– It is just that I think there are more urgent issues to address than to discuss the “formation of world systems.”
But I can see your “thirst” to figure out those issues. So, I will go through a quick point-form summary.
1. The Buddha said that only a small cluster of 10,000 world systems is destroyed at a given time. The whole universe will never be destroyed.
– A world system is a planetary system around a star. Thus, our Solar system is a world system (cakkavala). When one of the stars in such a cluster blows up in a supernova, the whole cluster of 10,000 will be destroyed.
– As I remember, there may be a few such “blowups” per year in our Milky Way galaxy, according to scientists.
2. Many cakkavala within a 10,000 system may have living beings located around a planet in each cakkavala. In ours, it is the Earth. All 31 realms in our cakkavala are based around the Earth.
– Living beings with “denser bodies” live close to the surface of the Earth. Devas in the Deva realms have “less dense bodies” and are far above the Earth.
– Rupavacara Brahmas live even further, and arupavacara Brahmas (with just hadaya vatthus) the furthest.
– Well before our cluster blows up in a few billion years, all living beings would have migrated to the Abhassara Brahma realm.
– When the Earth blows up (together with the Sun and many other stars in the vicinity), only those realms BELOW the Abhassara Brahma realm would be destroyed.
– Thus, all existing living beings can live at or above the Abhasara realm after that “blow up.”
3. Our 10,000 world system (let us call it our “cluster”) will be in that state for many billions of years.
– During that time, those Brahmas will gradually start “re-building” the material world (i.e., the Sun and the planets, including the Earth.) The same will happen in all other cakkavala in the “cluster.” That will lead to re-emerging of the “missing matter” in the “cluster” over many billions of years.
– It is the javana citta of those Brahmas over billions of years that will make enough suddhatthaka to re-form the whole system.
– Even now, we humans also make suddhatthaka, but those are in insignificant quantities. But uncountable Brahmas over many billions of years can make enough matter! Unlike our javana citta, Brahmas generate intense javana power. That is why yogis who can get to jhana samapatti can “generate” material objects like flowers or even larger objects!
4. What I very briefly described in #3 is the short answer to your question.
– When the Earth is re-formed (not the same Erath, but similar), then those Brahmas in the Abhassara realm will gradually be reborn on Earth as humans.
– That cyclic process has happened uncountable times in the past. That is why the Buddha said there is no discernible beginning to the rebirth process (Samsara).