As a rule of thumb, exclusive to a single chain means just that: you can only get that item in that chain, in-store or online on their site.
The British are bit better off than mainland Europe, as typical US exclusives are sold there in equivalent (meaning same umbrella company) stores, like ASDA for Target or Toys 'R Us UK for, well, Toys 'R Us US. Prices are decent over there too. so chances are MP Soundwave will be released over there, but don't quote me on that. Try hitting up a few of our sneaky Brits on the boards.
May I ask where in Europe you're from?