I don't know if that's mentioned in the attached video, but RE2 being a genuine 2 discs game is actually a false assumption. It was meant to be a single disc product since the very beginning. Unfortunately, they miscalculated the size of some audio assets, which forced them to suddenly change their plans. This is mentioned in the Alex Aniel book "Itchy, Tasty" where he interviewed many devs including the director himself Kamiya (if I remember correctly, he's the one who commented about this in said book).
However, being forced to go for the 2 discs format also made the game look "bigger" and more appealing to the audience, so you could say that from this accident the game was perceived in a better way and as a de-facto evolution of the first title of the series.