It’ll be optional. There have been many discussions about the type before or after the function name, and this was chosen in respect to C++ and general habits PHP devs have built over time. Perhaps in the future, but I’m not at all bothered by this in the age of live templates. I just type “pfa ” in PhpStorm and get
public function functionName(): array {
}
The namespace syntax has been debated to no end, and this was the best solution at the time. What would you like to have instead? What bothers you about the backslash that much?