All things considering (new platform, lower install base, port of a title that had a regular release in Japan only a few years ago), it did on the lower end of fine. The first Xenoblade didn't really do that well in Japan, and, according to an Iwata Asks, did better overseas. Regardless, I don't think the success or failure of Xenoblade X in Japan is necessarily indicative of the franchise's future.
Golden Week will help, for sure, but I also think given that it's a sequel and that it's released during Golden Week, it probably won't have the best legs. Even doing what the first Xenoblade ended up doing in Japan (~140k?) in its lifetime would be fine, I suppose.