dev-python/PyQt5-5.10.1-r1 supported both. If anything is dropped shouldn't it be qtwebkit?
This is simply following upstream changes: commit 1252c19b894ba758e02a5efe468b9771bc76923c Author: Davide Pesavento Date: Thu Dec 27 20:39:19 2018 +0100 dev-python/PyQt5: add 5.12 snapshot Added support for QtNetworkAuth. QtWebEngine support has been removed since it is no longer present in the source tarball and will likely be packaged separately.
We're merely packaging what upstream provides...
And yes, we will add PyQtWebEngine[1] as a separate package at some point. [1] https://www.riverbankcomputing.com/software/pyqtwebengine/download
*** Bug 675906 has been marked as a duplicate of this bug. ***