This is not a normal forum conversation though. It influences binaries on billions of devices. Lattner wanted to push his own opinion and got (IMO) gently rejected. Fair enough.

Lattner's point was that high-level design considerations should be thoroughly discussed well before even finalizing the design, never mind the bikeshedding on syntax that takes up much of the thread. Swift's design discussions seem severely dysfunctional compared to how other languages do these things, e.g. Python's Enhancement Proposals, Java's Community processes or Rust's RFC's.

Well if the topic is a minor syntax sugar (if let), then you need to talk syntax. I don’t see any bikeshedding here.