In T50666 we decided that WMF wikis that enable VE should not show it in beta features as well. This was done with a hack by setting $wgHiddenPrefs = 'visualeditor-enable';. This means that on third party wikis VE still shows up as a beta feature. This is not necessary as there is already a preference in 'Editing' to disable VE.
Note that some wikis still require VE to be a beta feature, rather than an editing preference, e.g. pl.wiktionary.
To a similar end we should change DefaultUserOptions['visualeditor-enable'] to true.