My understanding is that every loan to or within MLS requires a purchase option. I suppose this is to meet those requirements.Here's a question. According to the article linked below, Frederico Bravo's contract with Boca ends next week. So, why would we have to pay $1 million to get him on a transfer?
http://www.empireofsoccer.com/federico-bravo-says-an-nycfc-return-still-possible-56281/
Or it could be more like what Falastur mentioned which makes a lot of sense looking at it from the outside.