User blog comment:Rappy 4187/Technical Update: October 12, 2015/@comment-4129195-20151012221927/@comment-5811199-20151013104119

DaNASCAT did mention that we would be getting the new process enabled soon: "We intend to have the Help:JavaScript review process live on our wikias by the end of the month. MediaWiki pages will continue to be whitelisted as requested."

- DaNASCAT

At the current stage, it seems pretty stable. We have it enabled on one of our wikis and nothing has broken down or anything, so I assume they're smoothing the edges out to be released to all wikis.