I just tend to think Gelb and Zolecki are pretty good at their jobs:
The front office is operating under a directive to remain below the $208 million threshold that triggers the luxury tax, according to multiple team sources.
That's not vague or speculative or worded in a way that makes you think it came from an agent or another team. That came from up high (at least two people somewhere between an assistant GM and the President). I guess you could interpret it as a leak designed to send a message to agents but that's meaningless if other teams have better offers anyway (as with Hamels).
That doesn't mean Middleton won't change his mind - or do exactly as he said, and bust the tax if he believes it's a situation where the team is one piece away from the World Series. And until they actually sign Gregorius (or not) or trade Segura (or not) it's kind of a moot point. But it's also not entirely up to him, and I'm not sure Middleton is really different than the Yankees, Red Sox, Dodgers or Nats owners (granted, they have all previously busted the tax, but have moved away from it, and it's practically collusion).
Arrieta coming off the books next year means we can sign another pitcher next year (or maybe pick up some $ in July). I don't think it means they'll happily go over to the tax just because they could be back under next year (and they also have to pay JT next year).
I think they targeted Wheeler because they knew they couldn't afford Cole or Strasburg and they're targeting Gregorius because they can't afford Rendon or Donaldson. To me that $9 million offer to Hamels tells you what they are looking to spend, and on what caliber pitcher. And there's still a bench and bullpen to address. Hope I'm wrong!