Implicit creation not blocked

In this case:

```
"keyA" : "keyA",
"keyB" : "keyB",
"keyC" : "keyC",
${dictParam.${keyA}.${keyB}.${keyC}} : 1
```

the implicit creation of `dictParam` is blocked (like expected).

But the same in standard notation:

```
"keyA" : "keyA",
"keyB" : "keyB",
"keyC" : "keyC",
${dictParam}['keyA']['keyB']['keyC'] : 1
```

is not blocked. Why not?

Both should be blocked.
