As far as I'm aware, it seems to be policy (and if not, it would make sense to) use the USE flag name `ssl' if an ebuild only contains optional SSL support for one SSL implementation. So, since the only optional SSL implementation for ecryptfs-utils is OpenSSL, the `openssl' USE flag should be changed to `ssl'. For reference: http://archives.gentoo.org/gentoo-dev/msg_0673a33fe75961e510872fd2c1044ced.xml
On the other hand, the package's metadata.xml explains it quite nicely: sys-fs/ecryptfs-utils:openssl - Enable dev-libs/openssl key module
Not really, not in this case, because it's not about SSL/TLSv1...