Not sure I'd read into that exceedingly heavily, but it does give some context to the idea of signing a guy with basically one tool. In any case, I think the ship sailed a little bit with Dyson with the option of Nava: Dyson was really more of a 4th option/bench type.
The Pirates now really need to decide if they have any interest in tapping into a weak market for cheap starting production. The downside is relatively minimal: you block a guy with minimal upside and expectations, and almost every player still available really doesn't block anyone in a total sense from earning more playing time, not to mention the question marks around Polanco's production and health.
Frazier is a useful utility and bench bat, and perhaps has some room to grow, but I doubt it, since the hit tool is his primary value, and especially as an almost everyday LF in PNC Park, his defense is a huge problem. In any case, he's a 1.5 win player maybe at most. There are tons of ok power options floating around out there, and this team sorely needs some more power options. Taking a flier on Dickerson for this reason seems like a bit of a no brainer to me, given the paper thin depth and his additional year of control. Or even CarGo on a short deal. He's 32 this year, and not going to get a huge contract - maybe he rebounds somewhat offensively, and can take advantage of the short distance to RF in PNC.
There are just so many viable options which amount to an easy 2-2.5 win player that are sitting out there. Or at least that take a stab in that direction.