That is a good point and explains the letter better. Apparently Intel cannot fulfill even minimal attribution requirements and the letter is a polite reminder for the company of its duties.
Which is pretty sad - even most crappy mobile apps have a page where they list all open source projects including links to source, license terms, copyright attributions, etc.
that the MINIX 3 developers openly say in their FAQ that different agreements with them are possible. I would bet such an agreement exists - I don't believe Intel's lawyers would have tolerated such a legal liability.
