It's certainly a joking jab at that debate, and while I'm sure he can appreciate the irony of overtaking Linux this way, stroking his own ego is not what this is about. He doesn't need that.

I think the reason he posts this is that, just like everybody else, he's not happy about Intel secretly introducing a massive security hole in their processors. Telling him they were using Minix on such a massive scale would have been polite, but it would also have informed Tanenbaum that Intel was running a secret OS on their processors.

What Intel did was not only foolish and harmful, it was also impolite. Plenty of people are addressing the foolish and harmful parts already, but the impolite part can only really be addressed by AST.