Sorry, but more detailed (and post Cataclysm) map don't pass as for me as retcon. For me it would some info from book 3 that is direct contradiction to info from book 1. Something like "Sargeras was corrupted by Eredars" -> "Sargeras started Burning Legion, invited and corrupted some Eredars".
Same apply to info from Legion/BfA/SL, I didn't notice any significant retcon from Chronicles or heard any examples, just "OMG they retconned chronicles". But I repeat, I didn't analize this info from all this sources.