Imminent on a geologic time scale? Sure.
Imminent on the scale of the existence of the human race? Yeah, even that seems reasonable. 500,000 to a 1,000,000 years gives time for a lot to happen.
Imminent on a human lifetime time scale? I wouldn't worry about it. So the AI wants to do horrible things. But it has literally no way of doing it. No more dangerous than the crazy loner teenager steeped in hormones and jilted by the one and only person of the opposite sex that ever spoke to them.
When robots can run match simple human skills like reproduction, ability to feed themselves, go several hours without refueling and so on the threat is way overblown. Many of the barriers to achieving these capabilities are not limits set by the intelligence trying to implement them, but the physical world.