Japan takes a step to limit the work of high school pitchers:
MyWorldOfBaseball.com
A pitcher may not start another inning if he has thrown more that 100 pitches. It is still unclear whether he can pitch the next day but it is a start. Gone will be the tournaments in which a pitcher throws 881 pitches in six games, such as Kosei Yoshida did last year. Depending on the rule he may now be limited to 600 pitches unless they also have provisions that require a couple days rest between outings.
The author hopes this leads to forcing high school coaches to develop more pitchers.
Now that there is an established pipeline for Japanese pitchers to come to the US for the big dollars, it behooves the Japanese leagues to nurture those young arms.
Nippon baseball looks to be turning into a bit more than AAAA baseball, though the best of the best will usually go to MLB.
Travel and time differences make a global league not possible, even with hypersonic travel.