The actual proposal[1] is currently on stage 3 on the standards tract[2]. Meaning that the spec is complete and further refinement will require feedback[3]. Should I be a little surprised to see this enabled by default before it reaches stage 4 (ready for inclusion in the next version of the standard)?

[1]: https://github.com/tc39/proposal-promise-finally [2]: https://github.com/tc39/proposals/blob/master/README.md [3]: https://tc39.github.io/process-document/