Just because they weren't directly attrubuted doesn't mean they happened either.
Your link was about what _could_ happen, in the future, and was 20 years old. Now we know that the projected increases in cancer didn't happen.
"There have been no validated increases in solid cancer reported from the liquidator cohorts, and observed increases in leukemia have been statistically insignificant. The liquidators were adult at exposure and the average external dose was 117 mSv.
A paper in Science has stated that there have been no transgenerational effects of radiation exposure in children born of those working as liquidators. This study used whole genome sequencing in a cohort of parent and child blood samples"
... and apparently that report in itself was highly biased:
"However—as an April 2006 special report in the peer-reviewed, scientific journal Nature detailed in response—the accuracy and precision of this United Nations-led joint group's projected death toll of 4,000 were immediately contested, with several of the very scientists, physicians, and biomedical consortia whose work the joint group had cited alleging publicly that the joint group had either misrepresented their work or interpreted it out of context."
https://en.wikipedia.org/wiki/Deaths_due_to_the_Chernobyl_disaster