This is because at the age of seventeen the average British teenager is far too old for the kids clubs but won't be allowed to drink on any of Royal Caribbeans cruise ships until they turn 21, (you can read the full article here).
Now I'm not claiming responsibility for their policy change, I'm just saying it's a bit of a coincidence it happens a week after I write about it.
Hmmmmm, yes I know, I've got a big head!