Cant say I've any experience of just cutting a top out and leaving the trunk, but a large Cordyline will continually spring out from lower down, so I would cut it back further and wait and see. I think you will need to protect the cut during the winter to stop water soaking in the top and freezing. I'm sure someone will be more helpful! Be interested to know how it goes!
Hi, I agree with landscaper2 here and think it's more likely to produce basal shoots around the trunk but it's also possible it could sprout from the trunk, like some yukkas tend to do.
I think it may be worth waiting to see what happens and cut just above any new growth after it's appeared.