They establish that’s a possibility but didn’t say for certain… Either way, it can and has happen to any company, it’s just kind of ironic that this would happen to Adobe because of their own software and while in the midst of the CC backslash.
The bigger revelation in that article is that the attack actually happened 2-6 WEEKS ago (there’s two contradictory statements, at least the way I read it), and that Adobe was semi-clueless about the severity until the article’s writer contacted them… At best it seems like they were aware but were trying to keep it hush. That’s absolutely the worst possible way of handing a debacle like this.
It can happen to anyone, and at the end of the day it has little to do with cloud computing itself (the cloud might put you slightly more at risk but proper security layers like 2-step authentication can largely mitigate that), not being honest with costumers is by far a bigger issue IMO. I’d be far more trusting of a company that reacts faster, issues notifications in a matter of days etc (and plenty have done so under similar circumstances).
Honestly, the fact that this happened doesn’t surprise me and wouldn’t dissuade me from using CC, the fact that Adobe’s handling it so poorly is far more newsworthy and DPReview should consider updating the post or following up with additional details.
Not forcing a password reset on next login is another huge gaffe on their part that only helps to empower the criminals that are already profiting from this. If Adobe doesn’t compensate their costumers appropriately for their troubles (beyond the one year credit monitoring) I’d say they get an F for thhandling of the situation, which to me counts for more than the actual breach.

Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.