The new proposal for SE-0092 "Typealiases in protocols and protocol extensions” is proactively approved for Swift. The core team consider this as an obvious follow-on to SE-0011, and thus doesn’t itself demand a proposal. However, including a proposal in the swift-evolution archive does have a benefit to keep track of the new capability it enables.
The core team accepted this without a formal review period (because it its obviousness) as an attempt to optimize process. If there are any serious concerns, please raise them and we are happy to reconsider and start a normal review cycle.
I filed SR-1539 to track this effort. Thank you to David Hart and Doug Gregor for the proposal, and to Greg Titus
for already starting the implementation work on this!