I doubt it. As ktf indicated earlier, most of the changes affect specific use-cases: chances are that if they were relevant to your collection, you would already know that you needed the new version. AFAIK, beyond the fixes and additions specified in the changelog, very little has changed on the level of the format itself. I suspect recompression would yield little or perhaps even no benefits.
For it to be worth your time to re-encode everything, the new version would have to offer a pronounced increase in compression. In reality, it seems to be a refresh as the new maintainers deal with some old issues and add some new features, rather than delving deeply into the encoding process itself. And, to be honest, FLAC has never seemed to be targeted directly at maximal compression or users who worry about it, preferring to reach acceptable compression and then focus on other things. Time will tell whether this trend continues, but were I to be presumptuous, I would predict that it will.
For it to be worth your time to re-encode everything, the new version would have to offer a pronounced increase in compression. In reality, it seems to be a refresh as the new maintainers deal with some old issues and add some new features, rather than delving deeply into the encoding process itself. And, to be honest, FLAC has never seemed to be targeted directly at maximal compression or users who worry about it, preferring to reach acceptable compression and then focus on other things. Time will tell whether this trend continues, but were I to be presumptuous, I would predict that it will.