In case anyone missed it, the latest version of yay (v13+) supports being able to skip recently added packages through its new Lua extension system https://jguer.github.io/yay/lua.html#upgrade-selection-hooks. You can control the threshold since it's just user configuration now.
Nothing protect you from a `yay -S foo` install and its dependencies. So this is not a guarantee or enforcement of a minimum release-age.
Actually writing this reply I went ahead and pointed that out in an issue at: https://github.com/Jguer/yay/issues/2883