FYI, I noticed the same thing. Using the seed above, it is a similar world, but not the same as the one in the Let's Play. The village at spawn is there (although not the same layout/buildings), but the adjacent tropical biome is spruce woods or something. That was without any changes to the pack downloaded from the Curse launcher. I've since copied the pack over and made some config changes so it doesn't really matter to me anymore. Just wanted to mention that it wasn't only SummerFlower.