No. Rust has always had C-family syntax. You can look at the first public commit...

chrismorgan on June 24, 2018 | parent | context | favorite | on: Rust 2018: an early preview

No. Rust has always had C-family syntax. You can look at the first public commit with the code at https://github.com/rust-lang/rust/tree/d6b7c96c3eb29b9244ece... ; src/test/run-pass shows lots of examples of the syntax.