From Liquipedia Warcraft Wiki
Channeled abilities require the unit to stay still while the spell is active. The spell ends if the channeling is interrupted with another action by the user or canceled by an enemy interrupt.
|Balance Patch History
- Channeling ultimates now cancel invulnerability. If an invulnerability spell is used while channeling, channeling will end.
- Fixed channeling units so they will auto-queue orders issued to the entire selection except for Stop and Hide. Orders issued to the selected subgroup will break channeling (so you can teleport out of the area while channeling).
- A Hero channeling a spell will not stop casting the spell when a group containing this Hero is given a new command. The Hero must be individually selected in order to be given another command.