The article doesn't support anything your title says
they (and the Egyptians) invented
So you mean the Egyptians invented it and the Greeks/Romans simply appropriated it like they did everything else.
Conveniently forgets the whole dynasty when Egypt was ruled by Greeks
Um, its from when Egypt was Greek.
Possibly. The article doesn't make clear which is older.
We know that Plato and co did a lot of chatting about the shape at least. Since the period of Egypt that these old dice come from is the Greek-influenced Ptolemaic, and Rome was pretty big on its Greek culture anyway, I wonder if it started use there?
I mean... You can play D&D with 6-sided dice, 4-sided dice, a deck of cards, matchsticks, rock paper scissors, /dev/random, bones with symbols carved onto them, and leaves in the wind.
The Egyptians also invented the five-sided dice but they were too huge to roll.