I think it's ambiguous.
I would agree as it is presented currently they are powers, as that is what the text says.
However, in the PHB, every class feature that is a power (Mage Hand, Lay on Hands, Healing/Inspiring Word, etc) is presented as a power under the powers section of the class. The Warlock pact boons are not. Furthermore, AP doesn't once refer to the pact boons as powers. Neither the feats in PHB nor AP refer to the pact boons as powers. Finally, they don't have keywords, a fundamental part of the power design. This suggests to me that they are not intended to be powers.
My suspicion is that poor wording was used in the pact boon explanation.