I just read a post about Aegon theories in ASOIAF and think this writer is going to be very disappointed in the book's ending. His assumptions seem very ill-informed as far as I can tell:
First off, he doesn't mention anything about literary criticism. Any hints and clues nonwithstanding, G.R.R Martin is a great writer.
Having a character such as Aegon, who doesn't appear until halfway through the series, become one of the "three dragons" (and therefore a main protagonist) would almost certainly be a deus ex machina, and I just can't imagine Martin lowering himself to a kind of pulp fiction that would invoke disfavorable reviews from pretty much every literary critic alive today. The writer of the above article may know a lot about Martin, but he doesn't seem to know much about great literature.
Having a major protagonist showing up halfway through a work, and then spending very little time with him in the second half, and then not having him become a major part of the story until the last quarter of the series where he becomes as integral to the plot and climax as the main characters we've read about from the beginning... is something we are told is amateurish in Creative Writing 101.
Furthermore, the writer's reasons for Aegon being legit are not as strong as the reasons others have found in the works for his being false:
And lastly, this guy believes that Tyrion is Tywin's son, which he almost certainly is not, and there are many more clues that point to him being the product of the Mad King and Tywin's wife:
But the most damning evidence of all is still simply that deus ex machinas are poor writing, and Martin doesn't do poor writing.
This wouldn't be subverting a trope, it would just be poor writing, as bad as having Jaimie and Braun show up in the middle of the day at the same time as the Sand Snakes would be.
And Martin would NEVER do something as Hollywood as that, though the producers of the series obviously would...
Furthermore, seeing that there's still no Aegon in the series, Jorah has taken Connington's parts, and all of the symbolic references to Aegon have been left out of the show...and knowing that both the producers and Martin have said that the series and the books will wind up "in the same place"...we know that Aegon is not a major player in the end. Even if he were to die before the climax, being true born would make his story arc pointless, as well as all of Martin's carefully laid out innuendos and prequels concerning the "Blackfyre Rebellion" itself. The readers need to know the end of that story arc,;why the Golden Company changed their creed to join Daenarys, etc. Blackfyre story closure is necessary to complete several other character arcs as well. But it will definitely not culminate in Aegon being legitimate.