The three MLS teams fit the criteria because, arbitrary division designations aside, the level of play between MLS & CPL/USL will be vastly different, likely forever. The same cannot be said for the difference between CPL & USL - a difference which (IMO) will favour USL in the initial years, though the difference will likely not be vast (or in the language of the day, exceptional).
Tying MLS & CPL together because they're both Division 1 leagues is a false equivalency; the phrase refers to a position on a pyramid, not necessarily a level of play. That level of play is the exceptional circumstance that keeps (and should keep) the MLS teams separate.
That said, completely fair point on the second sentence - there's been some massive failures in communication here, and I'm not convinced it's unintentional.