NTSB: Cloud shot up vertically in front of plane before turbulence

It reads like the clouds moved that quickly which would indicate some kind of crazy updraft.

Before anyone Monday-morning quarterbacks this - no, there wouldn't have been anything the pilot flying could feasibly have done to avert this outcome in the "one to three seconds" between becoming aware of the updraft and entering it.

Even if it were possible to turn sharply enough to avoid the column of rising air, a maneuver that hard would very likely cause as much havoc in the cabin as occurred in the actual event - as a passenger returning from the lav, for example, being thrown across the cabin would likely not be preferable to being thrown into the ceiling, and maybe less so because at least there's no one else to hit on the way to the ceiling. Leaving that aside, even making the attempt might be more dangerous than not, since if they'd tried to evade and failed, it would mean entering the updraft in a relatively unstable configuration and maybe stalling a wing.

Like a cloud created by a UAP?

Turbulence happens, and it’s often not possible to see it coming. Air is transparent after all. I’ve never been on a flight in the US where the preflight safety briefing didn’t say that seat belts should remain fastened when you’re in your seat. But I’ve also never been on one where i haven’t observed people being pretty damn casual about it when we’re at cruise. It is probably time to specifically add something about turbulence to the briefing requirements.