Why do you think would they have to answer him anything? He published something, using a license saying you could use it without telling anyone nor giving back changes, and that's exactly what Intel did. And in his letter he acknowledged that.
It's an interesting question. Legally, they don't owe him anything. But from the point of view of social interaction, it's just extremely weird. Imagine someone using the project of your life in something huge, contacting you about some minor details - and then disappearing, so that you learn about it by accident from someone else. It's just strange. Not to mention that if you contact them about it, they should respond. In whatever way. Like, "we're sorry but it was an internal project that we weren't allowed to disclose" kind of way. (Intel guys reading this, it's a good hint!)
There was no call nor need for an answer...