Hasbro has agreements with the retailers that limit how much they can sell direct to consumers via the HTS site. TRU, Walmart, and Target don't want Hasbro opening a pipeline and cutting out some of their retail business...
So yes, in theory Hasbro should be the first to get them and should have an unlimited supply... but that would tick off their 3 major buyers, so they don't do it. Simple as that.