A have a little doubt about the Treasure of Champions, if this is not the right place to ask, please, let me know or move the post to tue correct place.

My question is: in the "Treasure of Champions", at the end of the item descriptions says: "The unusual couriers that may drop from this chest can only be found during the international.". Does this means that, after the international begins(a couple of days from now?), some couriers may drop with unusual effects? I know that couriers are already dropping, but this sentence made me confused. I have some keys but I dont know if I should open the chests now or wait a little longer and have a chance do gain better rewards.

Thanks in advance.
Ps: english is not my main language, if the text is confuse please let me know, I can try to rewrite it if needed.