I tried to widen the naming possibilities by allowing to use keywords as identifiers (for function names, class names, label (goto) names, ...) where possible. It doesn't break any BC.
Furthermore when BC needs to be broken in future for new keywords, it will have a smaller impact as most usages of the new keyword then still work.
It also prevents unnecessary workarounds like in https://wiki.php.net/rfc/named_params#syntax. There, to address a function with a parameter called $array, we could simply write func(array => $value); instead of the until now necessary func("array" => value);