While this is true, and Dracula XX is listed as a title that documented the event, Creator intent for Symphony of the Night was that it continued from RoB's perspective, not Dracula XX. IGA's said, in the past, that SotN was created to continue on the story from Rondo of Blood, specifically. And in no way, in the past, has Dracula XX ever been refered to as "Rondo of Blood", hence IGA knew what game he was connecting SotN to, and what game he wanted to be the representative of those events. It's only further pushed by IGA's bias for the games he love. RoB is one of his top three(quoted as being his second favorite CV game of all time, following closely after CV3), and we all know his bias is a big concern in how he makes his games. And while personal enjoyment or following of the canon timeline is subjective as long as the events remain the same(interchange RoB for Dracula XX), to see the canon as how IGA wants it to be seen, by his intentions and intentions following that which paved the way for SotN's development, RoB is the game which depicted Konami's canon, until IGA or a new developer says otherwise.