I think it would be extremely unusual for a Japanese Aikido teacher in Japan to talk about ki in the dojo.
It would be extremely unusual for a Chinese martial-arts master not to talk about chi in the dojo as well as outside the dojo.
Chi is everywhere and it's very real. In fact, everything is chi — light, heat, and even matter. (Ever hear of a nuclear explosion?)
But the chi that we commonly talk about and utilize in martial arts, sports, and the healing arts is the life force.
As we age, sustaining the life force becomes more and more vital.
Getting the flu shows one what it's like to have one's chi drained. Recovering from an injury is a good challenge in learning how to circulate and stimulate one's own chi.