The "article", or, to be more precise, blog post, is garbage.
It begins with a stupid assumption; that, because other quarterbacks in Barker's position transferred, then Barker is also likely to transfer. That's stupid because Barker's choices are not dependent on what other choices were made by other quarterbacks. But only is the premise stupid, the actual comparisons are apples to oranges.
First, it does not matter whether Barker is going to be in his fourth year when Towles presumably leaves the program. What matters is that Barker will be a junior with two full years of eligibility when that happens. So, the blogger/intern gets off to a bad start when he limits his compared players to fourth year players; it should also include third year juniors. An incoming junior has two years to play, whether he's a fourth year player who redshirted or a third year player who did not. Jeremy Johnson waited two years to have a chance to start; he is a junior; he did not transfer. Barker will be in that same position in 2017; so, if the blogger was unable to find a recent guy who stuck around and didn't transfer, Johnson is the example. That he's a third year player instead of a fourth year player is irrelevant; he has two years of playing time as a starter, just like Barker will.
Second, every single player who transferred was in a much different (and worse) position than Barker.
Phillip Sims was stuck behind AJ McCarron. Since McCarron, who came to Alabama one year before Sims, redshirted, that meant that Sims, if unable to beat out McCarron, was going to get one year to play as a starter- if he could stave off Blake Sims, from the same class, and every hot prospect to follow. Phillip Sims had a lot more reason than Barker to want to transfer.
Kiehl Frazier was stuck behind Cam Newton only for a year. He failed to pan out and left when he couldn't seize an open job.
Jacoby Brissett was in the same class as Driskel. He wasn't in a situation where he could patiently wait for Driskel to graduate, and then start for two years. He didn't have Barker's luxury of being the heir apparent for two years. As it turned out, he might have ended up jumping Driskel anyway, but at the time, nobody expected Driskel to regress and so transferring was probably the best option.
Christian Lemay is probably the closest comparison to Barker, in that he would have had a path to start going into his junior year, but he apparently wasn't as good as expected, and Hutson Mason or someone else might have beaten him after Murray left, so Lemay had reason to look elsewhere .
In the case of the LSU quarterback, they take at least one stud every year at quarterback, and they also got Mettenberger as a transfer. Randall was in a logjam, was guaranteed of nothing if he stayed around.
Peterman got brief chances at Tennessee, but never panned out. When he jumped by a guy who came after him in Dobbs, the writing was on the wall.
Same with Kenny Hill. Jumped by a true freshman and with Kyler Murray the next hot prospect in line. Hill could transfer or spend the rest of his A and M career watching Allen and/or Murray.
None of these guys were anything close to clear cut heir apparent that Barker is, and every single one of them had much better reasons to get out of Dodge than Barker does. The closest comparison to Barker is Jeremy Johnson, who starts this year for Auburn.