I'm running an up-to-date KDE neon user edition. Currently we have: Package: kwin-common Version: 4:5.12.2-0neon+16.04+xenial+build85 Recommends: kwin-style-breeze, libqt5multimedia5-plugins, qtvirtualkeyboard qtvirtualkeyboard is transitional, having been replaced by qtvirtualkeyboard-plugin. kwin-common should recommend qtvirtualkeyboard-plugin.
Coming back to this bug report two years later, I can confirm this has been fixed in KDE neon 18.04.