To answer the first question this release addresses a serious bug introduced in the previous release. Morph mirroring was broken. That was fall out from fixing pose symmetry to work better with figures that have extra parts in 11.2. That of course was fallout from LaFemme and L'Homme having extra parts.

As for missing content. There was no content changes between these releases so no, it won't change that. Still, please backup your runtimes. You'll sleep better.