In Chapter 12 of the 9 School Competition Arc, Kazama and Kudou talk about Tatsuya
Kudou tells Kazama:
"Yesterday's match was quite entertaining. While I hear that it was the only successful example, I didn't imagine that it would be that powerful."
A few lines earlier
"It's hardly surprising that I would know about it, right? Three years ago, I was conveniently the chairman of the committee for the Ten Master Clans and currently remain a magic advisor to national defense. Also, though it was for a short period of time, both Maya and Miya were my students."
-> although that refers to Tatsuya joining the 101st Magic Battalion, but it hints on his relationship with both of them, and most likely knowledge of Miya's ability.
I wouldn't be surprised if he played a part in the conception of the experiment.
Again I offer this
Also, though it was for a short period of time, both Maya and Miya were my students.
In the same chapter a few line later Kazama drops this
"Sir, just as you know the details on my side, so too do I know a few things on your side. I know the real reason why you are so interested in Tatsuya's situation."
So following the hints, I provided, I postulate the following:
Kudou knows not only Miya and Maya, who were his students, but also is aware of their abilities (of particular importance is Miya's mental interference magic), he was aware of the experiment (possibly helping to conceptualize it), due to the events of "three (four as of d7) years ago" during the okinawan invasion Tatsuya became part of the military, which did not escape Kudou's notice, and connecting the dots, he not only realized/figured out that he was Miya's son (and as such a Yotsuba) but also had the experiment performed on him, successfully.
But that is not the only reason for Kudou's interest in Tatsuya, but, as of now, we do not yet know the underlying reasons for it.
Is Zhou's master a Dahan survivor? In Volume 12 Chapter 15 (D7 Arc)
(In the end, the Master’s true feelings on the matter are to have his revenge against the people responsible for bringing out Great Han...... The real target is not such a vague organization like “Japanese Magicians”, but that clan in particular.)
I can only guess that "that clan" refers to the Yotsuba
Imagine his surprise when he finds out that the person who foiled his plans twice, is a member of said clan (even if disavowed).
Maybe Zhou (or his master through him) will try to get back at Tatsuya by targeting Miyuki and/or his friends ... ass dissolving is sure to follow.