I already knew that and that’s irrelevant to the point here. RSS lacking an updated time stamp doesn’t give meaning to a comparison between updated and published timestamp. If it does, please show me how.
We’re specifically talking about the case when the user explicitly chooses to trust potentially incorrect feed data. We’re not talking about default sorting. If I choose to sort by feed dates, It should be consistent to minimize confusion. The result of comparing published and updated dates has no meaning.