Do not get this point;

"Reclassifying a HTM security may prevent the holder from classifying other debt securities as HTM, or even other HTM to be reclassified as AFS"

Why would it prevent other debt securities to be HTM?

You’re studying late, today.

Because the SEC dislikes it when companies lie to them.

If you promise to hold a security until maturity, the SEC expects you to honor that promise. If you reclassify enough of them, the SEC get angry and says that you’re not allowed to classify them as HTM for a while.