The ESS package in Emacs has also had several of these features for R for a long time. The difference here is portability and generality. Tree-sitter is a partial solution to the n×m problem, and now R has been invited to participate in that solution. That's something to be celebrated, even if it doesn't have immediate impact on our day-to-day, because it means future innovations in tooling for programming languages get automatically shared to R, instead of having to be reimplemented.

(The n×m problem is that for n languages and m tools like autoformatting, etc., we need an implementation for each tool specific to each language. With tree-sitter, we get n+m implementations instead: generic tools that work across multiple languages.)