The second review of "SE-0109: Remove the Boolean protocol" ran from June 28 ... July 4, 2016. The proposal has been *accepted*:
The community and core team are overall positive on the removal of the Boolean protocol, under the rationale that it is not pulling its weight and its name is confusing next to Bool. Several members of the core team and a member of the community points out that the *functionality* provided by the Boolean protocol could make sense for Swift if a well-considered design was available, but the core team feels that we should remove Boolean for Swift 3, and consider adding back a replacement when and if a compelling use-case presents itself to motivate that work.
Thank you to Anton Zhilin and Chris Lattner