Don’t make light of his advice, if not you might lose your life.
A loyalty announcement is the kind of announcement you give to someone who you're loyal to. To this type of person, your announcement would come in the form of advice or maybe admonishment, if you're upset with what they've done.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.