If you trade Trey (or Lopez or Santander or Lyles) you're pretty much white flagging the playoff race. That doesn't mean the team can't stay in it, but its saying that you aren't trying to win it at the above-the-field level.
I'm not against such a move, I think the playoff odds are wildly low. .
I think the odds are low too. Without checking, I'd guess Wells, Kremer and Watkins are all approaching career high inning totals for a season. I reluctantly expect some drop off after that point, and as much fun as we've had recently, it was mostly against struggling teams.
So, at the FO level, the decision becomes a choice between trying hard to maybe squeeze into a WC spot, or build even more depth for the anticipated run of good years ahead. I'm somewhat ok with the latter, even if it means an ugly finish to this season.