Whats the big advantage of Trailing commas are allowed in parameter lists? I never liked it, if its not there, dont do a kind of pseudo initialization.
It makes diffs easier to read, and ensures you never forget to add one of you'd add a new line to the parameter list.
Maybe not for single line calls, but for multi-line helps with some readability and git diffs.
$result = thing(
$arg1,
$arg2,
$arg3,
);
One of important weakness of php language is loosing generic type, I think this is one of most important feature we need in php.