The interesting implication of this (imo pretty nutso) move by Jeff Gural & Co. is that it is now very highly likely the best 3yos will still retire at the same point they always have only they'll stand their initial season at stud in the Southern Hemisphere then head back North to stand as per the specs above & things will continue as per normal.
Not that they all fitted the above mentioned age criteria however it is not as though there is no precedent to that happening. As I recall Badlands Hanover, Sportswriter & Artistic Fella all stood their initial season at stud here in the Southern Hemisphere and there may well be a few more of them that I've forgotten. As always, every cloud has a silver lining.