I wouldn't say it "tells" you he's throwing cookies in an attempt to throw more strikes, that's just what you assume. A quick look at First Strike % at fangraphs makes the possibility that this is the case smaller. He threw 60% first strikes last year, this year it is 55%. If he's intentionally throwing strikes at the risk of being over the middle, more of his misses will be over the plate, and he'd have a higher FS%.
Orel Hershiser spoke about the effect of a longer season during one of his (Lester's) starts. He talked about not being stretched out and comfortable early in a season after playing deep into October and logging more innings than before. Then he went on to explain how command was the first thing he struggled with when he felt tight. It was like the Verducci Effect, but with credible reasoning and explanations for performance that made sense.
Getting hit harder, and throwing less first strikes, suggests to me that he's missing location more. If he's setting up outside and misses, then it's a clear ball or over the middle. Fewer strikes, more hits. This, and the idea of being tight and struggling with command per Hershiser, makes more sense to me.