Depends on server. ARR S ranks get called sometimes in my hunt LS. Pretty much never see call outs for ARR A ranks and its rare to really see them on Ultros because normally someone runs into it and just murders it solo just because its there whether its someone gathering or leveling another job. I solo killed a few just because I happen to run across them when they re-did the yo-kai event... so many fates just for a glowing ghost mount...