Every time a new Crystal release comes out it inevitably gets delayed for macOS because it has to wait for approval from the home-brew core team. I think this is totally reasonable for them to do, but it does make it hard for the Crystal community because some libs work for newer versions but can’t be easily used on Mac.
My suggestion is to have a crystal home-brew tap so the core team can release whenever they need. This is what we do for Lucky https://github.com/luckyframework/homebrew-lucky and https://github.com/paulcsmith/up. It is only one extra step
brew tap luckyframework/homebrew-lucky and then works just like normal.