I think this is a good development for junior rugby. From what I have read so far the ARU has been smart enough to look beyond a simple concept of size.
My problem is that there has been ZERO communication to players on this policy even though it's registration time. Players and their parents are, right now, making decisions about registration and all we have been told is the motherhood statements in newspaper articles - which have the appearance of a PR campaign. Not a single detail on the many questions arising (how will this policy be applied, who will be affected (what exactly are the size parameters?), when it will kick in, whether it affects rep rugby or just club rugby, how will they deal with circumstances where a player should be regraded but there's no team for them to move to etc).
My son is likely to fall under this policy based on what I have read. The result of learning about this policy is that his registration is now on hold until we know more because he has already said that he is unlikely to want to play club rugby if he can't play in his current team.