Yeah, it's probably the easiest conclusion. I'll add just a little to the article, only because I caught a few things looking at his pages, and some thoughts, but Ben's probably the authority here.
Which makes him an interesting use case for the Cubs - a team who *loves* their fastballs this year. His fastball has lost velocity (about half a mph on average), He's been on a pretty decent downturn on fastball shape according to Stuff+ year-over-year as well, though BP's stuffpitch+ and propitch+ think it's not overall different. Just checking Savant, he's getting more rise on the fastball than he had been despite the similar arm slot. Ben mentioned this as well.
BP's deserved +/-, however, suggests he's not been very good and he's earned it.
A few other things of note; he's throwing more pitches in the zone, getting less chases out of it, The positive is that he's generating more whiffs on chase than normal, but it doesn't seem to be anywhere near enough to offset things.
I'd say that if Tyler Zombro sees an easy, internal fix here, then he's probably worth a look, but as with a few other pitchers who are going to be available, they feel more like "fixer-uppers" and in two months time in a new org, that could be a stretch as they head into October. But with how the Cubs have emphasized fastball and Gallen has is struggling with fastball, my gut reaction is that the Cubs won't be enamored by him unless Zomrbo and Co have a quick-fix for the fastball they can implement.