With Elektra possibly being set up as a second villain for The Defenders, it’s even more likely that the Hand will play a role and the Chaste will be called in to help the Defenders take them down.
We’ve already met both Stone and Star briefly on Daredevil, so the arrival of more members of the Chaste has always seemed likely.
With a proper trailer for The Defenders likely on the horizon, we should know more soon.
Another possibility is that the Chaste are also working against the Defenders.