I don't think there is a need for any debate, it is after all clear what we mean: an ice age is the whole cycle (interglacial + glacial), glacial is the period

I don't think there is a need for any debate, it is after all clear what we mean: an ice age is the whole cycle (interglacial + glacial), glacial is the period of maximum ice coverage, interglacial is the period of minimum ice coverage. In the common vernacular "ice age" equals the glacial period.