This is a good question. We know from other passages in the Bible that God does not want anyone to suffer or to perish spiritually, and God certainly does not delight in evil! For example there is 1 Timothy 2:3-4. "This is good and pleases God our Savior, who wants all men to be saved and to come to the knowledge of the truth." In Matthew 23:37 Jesus said of the Jews who were about to betray him and have him killed, "how often I have longed to gather your children together, as a hen gathers her chicks under her wings, but you were not willing." Here we see a hint of how to understand Deuteronomy 28:63. God has given us a choice of whether or not we will come to him. He has already come to us. Those who reject that call will experience discipline and even punishment. Deuteronomy 30:19-20 expresses this sentiment well. God pleads with his people to choose blessings and life so that it would go well with them. The alternative for them is curses and death. The Hebrew word translated as glad or pleased in Deuteronomy 28:63 is sus which does have the normal meaning of pleased or delighted, but we should take it in the spirit and context of the scripture and of Deuteronomy 27-30. God is telling his people that if they choose to rebel against them, the intensity of the punishment they will experience is in proportion to the intensity of the blessings they will experience if they choose life. I take "pleased" in the sense as doing something without hesitation.
Bear in mind that in Deuteronomy 28 God is talking about applying discipline to his people for the purpose of winning them back to him. The book of Deuteronomy makes is crystal clear that God has given us a free choice, but also that we will be held accountable to that choice. God will discipline us and even bring harm on us for disobedience, not because he wants to bring harm, but so that he can bring his people to repentance and to blessing.
So, I take "pleased" in the sense of zealous and willing to discipline his people, not because he hates them but because he loves them. God so loved the world that he gave us a choice whether to love him or not, but then he so loved the world that he gave us his son so that all who believe in him should not perish, but have everlasting life.