This issue started with the delay of the release of Battle of Legends Monster Mayhem in Europe, and it can still be an issue in the future if more sets gets delayed, how should the legality of new cards in Ranked be handled if a set is delayed in one or more regions?
1 - Release them on the date they should have normally been released, those who have those cards available can test them in ranked and prepare for tournaments, those who do not have them, can try them while waiting for them to be released, i.e. as was done for BLMM.
2 - Don't release them until the cards are available to all regions. This doesn't change the meta for those who don't have the cards available, but it doesn't allow those who do have them to prepare properly for their tournaments, as has been done now for PHRE.
Each choice obviously causes divisions in the community, but if I had to choose, I would opt for the first, since it doesn't take anything away from anyone: those who have the cards can test them, and those who don't can play normally on the ladder, even if they encounter decks that haven't been released yet.
