This is the news:
You can now prioritize which of your players will benefit from a coach boost in training. Simply move a player up or down the list for a particular attribute on the Training Field. Players that are higher up in the list (and are not seriously injured or on training camp) will be the ones training along with a coach.
Does this mean players get a bigger or smaller coach-boost depending on their position in the specific training spot list? I never heard of such!
Or this is to correct the fact that if you have more than 5 seniors or 6 youths in a training field position, the last one does not benefit from coach bonus and this last is chosen by age??? Because I believe this is the case and the update is good - usually the youngest is actually the one who should benefit most but anyway, giving this option to managers is the right way.