Why even have commas at all? This is a non-issue for the likes of Tcl and Lisp and your average shell-scripting language and what have you; whitespace is already a good enough delimiter.
Having newline be a valid list separator is particularly nice because it solves the "trailing comma" and "comma-first" style workarounds in a visually elegant way. The newline already provides a visual separator; we can already tell that we're at the end of most lists by way of having another keyword appear next without needing to rely on a lack of commas, for example:
select
id
name
email
from users``` SELECT Field AS Renamed, OtherField AS AlsoRenamed ```
and
``` SELECT Field Renamed, OtherField AlsoRenamed ```
are semantically equivalent.
That said, generating SQL from s-expressions can be a very pleasant experience.