Earlier quoted context omitted.
Apparently not: https://mobile.twitter.com/amasad/status/1072930703065501696
Nuclide replaced FBIDE, the internal pre-setup web IDE that Facebook used. Having a pre-setup environment is a huge productivity boost: - dev env onboarding takes a minute instead of a week - employees can code "on the go" So predictably, if they get rid of Nuclide there needs to be an alternative and doubtful they've built something new because... why.
This announcement is about the open source version of Nuclide, which has never received a lot of love and didn't have a lot of adoption.