” Is God, in His divine nature, subject to pleasure?”
I would say, according to scripture, the answer is yes.
Isaiah 62:5, “For as a young man marrieth a virgin, so shall thy sons marry thee: and as the bridegroom rejoiceth over the bride, so shall thy God rejoice over thee.”
Zephaniah 3:17, “The LORD thy God in the midst of thee is mighty; he will save, he will rejoice over thee with joy; he will rest in his love, he will joy over thee with
singing.”
Matt. 3:17, “And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.”
Anthropomorphisms. Next thing you will tell me that God has hands because the "Bible says so."