You're totally right, I misremembered the autoclosure behavior.
I'm just concerned this feature might be too specific to a @Lazy macro or niche SwiftUI macros, resulting in needless language complexity. Namely, if the language doesn't allow closures to capture self in property initializers, why should the SwiftUI macro in the Motivation section be an exception?
If the only strong motivating example is an @Lazy macro, then this macro can simply use an underscored version of the proposed selfAvailable property. This way, we don't have to commit to a public API for all macro developers.