I love this.
Is it a ISOT, or something else?
No New Kingdom of Egypt? Or Persia?
Its not an ISOT, the basic premise is that throught the years many civilizations that have since vanished had a surviving colony/branch that made it to the New World. I am trying to make the world as Columbus would have found it when he landed. There is sort of an Egypt, the Egyptians sailed across the Atlantic and had active trade with the Mayans and several south american tribes which is how several Pharaohs have traces of nicotine and cocaine on their lips. Many Egyptians settled in this new land and showed the Mayans pyramid building and mummification. This is attempting to have as little ASB elements as possible. So far there has been evidence, although some of it weak, that at some point the countries shown here had contact with the Americas, the only exception is the Chinese settlement that was pioneered by Zheng He. Zheng never reached the America's but he was a prominent Ming explorer that traveled much of New Guinea and some of Polynesia so i figured it wasn't to much of a stretch.
TLDR: Not an ISOT, Egypt is still around but intermixed with the Mayans, this timeline is attempting to be as non-ASB as possible.