At this point, I don't think there is the need to offer php7 as a beta feature anymore. Logged-in users should be extracted to go to either php7 or hhvm as all other users.
In order to achieve this we need to:
- Make enableLoggedIn true in WikimediaEvents/modules/all/ext.wikimediaEvents.php7.js
- Disable the beta feature in WikimediaEvents
- Remove the code for enabling the beta feature (eventually)
Alternatively, we could decide to migrate all logged-in users before all the other users.