I'm pretty sure Sadogatake would have been allowed to finish the basho as oyakata, as Taiho was in May.
If it was announced in any official way that Kotonowaka would retire after today, he wouldn't have been
allowed to fight today.
Dale
We live in Japan and hear the NHK English broadcast througout the sumo and it WAS announced before the start of yesterday action that he was retiring and his wife and son were there to watch his last bout. The "official" announcement came after the bout, but everyone knew in advance.
The announcer said if Kotonowaka didn't take the name of the oyakata by today (Saturday here in Japan), his fellow wrestlers at Sadogatake would be ineligible to continue this basho, as the oyakata turned 65 today. I am not reporting this as fact, simply regurgitating what the NHK said yesterday.
(Nodding yes...)