PhoenixDark
Banned
Yup. Two of the biggest reveals in ADWD were "spoiled" for me due to fan theories (3EC = Bloodraven and Aegon). So clearly he isn't going to be changing any of his plot twists just because the fans are predicating them with surprising accuracy.
Interestingly, the original version of the ADWD Tyrion chapter he released had more blatant Aegon tells, which he did take out of the final version. Today the chapter has a scene where Illyrio is saddened that he cannot personally give some gifts to Young Griff, including some clothes. In the original draft, Illyrio mentions he has clothes and a sword he needs to give to Young Giff as gifts. It's commonly believed Illyrio was going to give Young Griff the Blackfyre sword. Martin may try to hide things but there are rabid fans (like Elio and Linda...) who literally obsess over everything for years, decades even. So for instance when Jon's parents are revealed I don't think anyone will be truly shocked; I've met fans of the show who have somehow heard that Jon isn't Ned's son too.
Westeros.org documents all the answers Martin has given to fans over the years. He has never outright said baby Aegon was dead; the furthest back reference I've found was in 2000
http://www.westeros.org/Citadel/SSM/Entry/1106/August 06, 2000
Elia’s Children
Fan: I was wondering if you could answer (or take the "fifth") one teeny little question I've been dying to ask for the past year: Are Aegon and Rhaenys, Elia's children, well and truly dead?
Martin: All I have to say is that there is absolutely no doubt that little Princess Rhaenys was dragged from beneath her father's bed and slain.
Personally I think the real Aegon is dead, but obviously Martin couldn't outright saw that at the time without ruining a future arc. It's perhaps the most controversial twist in the series in recent memory, with many claiming Martin pulled it out his ass...but I think Westeros.org has documented that this was long in the making.