This is also my overall position on it more or less. Much like the entire concept of the War of the Five Kings, whether he is or isn’t a Targ matters less than what people believe, and I’m confident that at least he and JonCon believe it themselves. However, if Varys/Illyrio know the truth, which they presumably do either way, that could matter in the end. Although once Aegon’s claim reaches critical mass, if either of them try to throw a wrench in the works they’ll probably just be dismissed or discredited even if what they say is true and they somehow have reasonable evidence, much like Stannis and the incest claims. If Illyrio can convince Dany of at some point in the future, however…