That changes a lot of things. For one, this side effect was neither known nor documented, so people could not make an informed decision before getting the vaccine.

Then individuals have a quantifiable risk of dying from COVID vs. dying from the vaccine. Depending on age/sex/comorbidities/medication/etc. one of the other may be higher.

Also from a public health perspective, if these CVST cases are known to be mostly limited to a particular group (women under 50) and the vector vaccine, then this group could be vaccinated with other types like mRNA vaccines.