The club seems to have changed somewhat its drafting and development philosophy recently, and this move appears to be the result. At the end of the 2006 season, the club ended its relationship with Pulaski in the Appalachian League, and it appeared that the Jays would have a major-league low of 5 affiliates in 2007. All of the leagues in which their 3 A ball affiliates play have a high proportion of college drafts.
Since season's end, the club has gained a number of high draft picks as compensation for lost free agents, and has indicated an intention to look more closely at high school prospects. The possibility of more high school drafts and increased signing activity in Latin America suggested the need for a Rookie League affiliate, and led to the Gulf Coast League affiliation.
Thanks to KevinJaysfan for the tip and link.