Ultimately, selling out initial shipments is good but the true test of Bayonetta 2's health will come in the following weeks. Most non-licensed or major franchise console games sell well for a week or two in Japan before dropping off. If Bayonetta 2 can hang around in the top ten for a while that will be a success.
But ultimately, I think the major push will lie in the hands of Western Wii U owners, healthy sales outside of Japan especially since we know Nintendo won't do jack outside of online trailers to promote it will probably determine whether or not we ever see a Bayonetta 3 and potentially the fate of original stylized action games in general this generation given the frosty reception several recent big names have received in the past year or two.