That makes no sense to me. Most of what makes Crystal different from Ruby results from the former being a static language and the later being dynamic.
I understand that dynamic languages are not popular these days on HN, but it's silly to suggest they should become static languages. They just offer different tradeoffs, a bit like screws and nails.
Dylan is a Lisp (thus dynamic) with Algol-like syntax.
Dylan supports AOT compilation like Crystal, and had optional type checking, so one could make it into Crystal if all variable declarations happened to be annotated.
Don't forget Dylan was intended to be used as Newton systems programming language and the team managed to create their own OS, even after C++ was decided to take Dylan's role.
Personally dynamic languages without AOT or JIT support were never popular with me beyond shell scripting tasks.
I understand that dynamic languages are not popular these days on HN, but it's silly to suggest they should become static languages. They just offer different tradeoffs, a bit like screws and nails.