QE noticed that the cancel icon is there only if the plan is canceled during the Precopy stage in warm migration (please see attached image).
In case the plan is canceled during the Cutover stage - there is no cancel icon (as in cold migration)

Mike responded:
Note: this is related to https://github.com/konveyor/forklift-ui/issues/473

Original bug: https://bugzilla.redhat.com/show_bug.cgi?id=2061643