I had crosschecked in the latest version of pega also and there is no way you can hide the column based on the condition in the report definition directly. There are only two ways which can help you are as follows:
Use the repeat grid and source the report definition then apply the visiblity based on condition as explained in my above comment.
Use the repeat grid and source it with the Virtual report definition. The virtual report data will be constructed by your activity and you can apply the visibility condition on it. For more information about the Virtual Report Definition Grid you can look into the sample example of the OOTB i.e. @baseclass • pxUIGalleryVirtualGrid
Hope this information might help you in achieving your requirement.