Is there a "norm" in the Upaniṣads?

Were "norms" already availble to the authors of the oldest Upaniṣads? If so, how did they identify the breaking of a norm? Can contemporary readers detect the authors' identifications of some episodes as counter-normative?
Sven Wortmann, using Brian Black's narratological approach (already discussed in this blog here), read a paper at the IIGRS2 conference in Cambridge on these themes. He maintains that through a narratological reading one can identify the cases where a norm is broken. Specifically, one could use as identification marks the following ones:

1. 1. the text explicitly indicates the content as counter-normative
2. 2. other texts indicate it as such
3. 3. the content becomes a motif
   
4. 4. the content is deleted in other parallel or later texts

To elaborate, S.Wortmann discussed two cases (the king Ajātaśatru which teaches and initiates a brahmin BĀUp 2.1, and Satyakāma and his mother Jāvalā, who does not know to which gotra his father belongs, in ChUp). The paper has raised a very interesting discussion. Personally, I can't see why point 2. should yield any evidence in favour of the breaking of a norm (there are many motives which re-inforce a norm or that are norm-neutral). Others objected against the very idea of the normative in the Upaniṣads, or against the examples chosen. Are casts already fix at the time of the BĀUp? Don't they rather refer to specializations (so that it is strange that a king initiates a i, but it is not counter-normative)?
A last interesting questions regard the context of this allegedly counter-normative motives: have they been composed by kṣatriyas? By urbanised (i.e., progressive) brahmins?