I think your observation is correct - the built-in reports are updated in 6.5. The Tape Summary report has the same output as you run "bpmedialist -summary -brief" command.
Call it a feature. :) It's all good.
Try run the command this way:
bpmedialist -summary | grep "(FROZEN)"
and you should get only the frozen tapes' ID without those unnecessary info.
Regarding your concern of "the name isn't even valid but a couple now have Active tapes etc.", be aware that you may have some old Media servers not decommissioned properly - NetBackup is telling you that these hosts are "Media Owner" and they own some tapes. Run the Tape Summary report again, but with the specific "Media Owner" selected (click the drop down menu), and the "Verbose Listing" selected, and see what tapes are owned by these specific hosts.