I expect you are right about the show writing out Aegon, but it’s a big disconnect. In the books, Jon Connington and Aegon get the Golden Company to Westeros and open the War of the Targaryen Restoration while Dany is still wandering around in horse country. Since the Golden Company is composed of exiles and the sons of exiles, its participation implies a network of potential supporters in Westerous and scrambles what we think we understand about the politics of the great houses as old Blackfyre connections are revived. The show (and for all I know, Books Six and Seven) may dispense with all that, but there is a lot of potential there that is being left on the cutting room floor.
When I started reading the first thing I noticed was how simplified the show was. Combined characters and such. Getting to the same place by a somewhat different route. Stuff they cut resulting in different plots for some characters.
Much less dense with the noble houses and some of the battles.
Personally being a political junkie even for fictional medieval politics, I love all that stuff!