elionExcept WOTC sells NOTHING. Every box is sold by a distributor, while in print. And after that, it’s another distributor selling to another sellers. So, no, WOTC has zero terms on a out of print magic booster box !
ask vintage magic dot com (for example) if WOTC has any legal rights to prevent them from selling a 4th édition booster box to ANYONE on the planet...
VanillaFWOTC has a policy enforced by their distributors that any sealed MTG product the distributor sells in the US cannot be sold outside the US until two years after its release date.
In order for a merchant to buy sealed product from a distributor, they have to sign a contract agreeing to those terms.
Iconic Masters was released in November 2017, so US merchants will be able to sell it internationally starting in November of this year.