[relay-compiler 13] Invalid use of @stream on scalar field #3755

With v13 (even on @main) I get error when using @stream on a List of scalars, while it works for objects.
Is this defined somewhere in the spec? It is not clear to me (spec for @stream) , just the field must be List type. The data in payload could be any scalar too.

type Query {
  alphabet: [String!]
}

alphabet: {
  type: new GraphQLList(new GraphQLNonNull(GraphQLString)),
  resolve: async function* () {
    for (let letter = 65; letter <= 90; letter += await bumpy(1)) {
      yield String.fromCharCode(letter);
    }
  },
},

query demo3Query {
  alphabet @stream(initial_count: 3)   // <== [ERROR] ✖︎ Invalid use of @stream on scalar field 'alphabet'
}

Note: the test is correct for such case, but it does not cover the above mentioned case but it is pretty much similar, just a different query field.

The above example works for this kind of query:

query demo3Query {
  alphabet @stream(initial_count: 3) {
    char
  }
}