Just watched this talk on the new Cangjie programming language from Huawei, where the speaker mentions Swift's reference-counting when explaining that they use a concurrent GC instead (edit: a better talk about Cangjie from PLDI 2025). An interesting green-field effort for the Swift team to look at, including the highlighted intro of effects handlers.
Also found this year-old blog post about zig's comptime meta-programming interesting, especially given ongoing work on Swift's approach.