I think that's the heart of it.Sure, there's the potential trade return to consider. But I'd argue that these sorts of "sign a guy for the sole purpose of dealing him to a contender at the deadline" signings fail far, far more often than they succeed. It's a low-risk move, so it's nothing to stress over, but it's rare for these sorts of guys to really play well enough to merit any sort of meaningful return.
It's conceivable that Gomes might smack around lefties for a few months and garner interest at the deadline. It's happened before. Realistically, however, it's exceptionally unlikely for a contending team to give up much of value for the short half of a corner outfield platoon, especially when the guy doesn't offer much defensively or on the bases. In the very, very best case scenario you probably get a guy who wasn't as good a prospect as Perez or Terdoslavich were in their minor league days.
Young...honestly, I don't think there's any realistic shot of converting him into something valuable. I agree he has his uses as the 24th or 25th guy on a playoff team, but those sorts are freely available talents, and most organizations have a player or two in the upper minors who can play multiple positions and run the bases. The best you can hope for in an EY trade is a PTBNL or cash considerations.