In my collection, I mark these as “pre-order bonus track”, and treat the release similar to a deluxe edition, but as a pre-order edition.
iTunes does similar with making a few tracks available early. Pirates call this pre-single, I mention that as I am unaware of any official name as it is part of the actual release and not an actual single (since most times any track on an album can be individually ordered). In my collection, I disregard those releases and consider them an incomplete release, or stand-alone recording of sorts. But it would be stored as x track on x album, nothing more.
That is just what I do to keep track of them, if it helps anyone else in their collection.