Adding elements to a map allocates memory and moves stuff all the time under the hood, it's no different from append. If panicking on nil is weird for append, it's just as weird for maps
append returns a new pointer in case the slice moved, map assignment does not return a new pointer. There’s no way for the operator to change the reference you hold from a nil to a pointer to the newly allocated value. When memory is allocated under the hood on assignment to a non-nil map, your reference to the object remains the same, but some internal pointers change.
You can write a func Set[k, v](map map[k]v, k k, v v) map[k]v yourself that returns a map reference if you want this style of “maybe return a new pointer”.
