Bug or feature? Field property created only with EQUALS returns false for has_key

[blattms]

If we use EQUALS to populate a field property without initializing it as a normal keyword before. FieldPropsManager::has_key will return false for it (because there is no entry in the list of keys).
This might be a feature because because FieldProperty::try_get explicitly caters for the case where the key is missing in the list.

Does anybody know why?

I still have the feeling that has_key should return true even in this case...