These sorts of trades -- the ones that build up your roster immediately, like the Pomeranz deal, like the Kimbrel deal -- are legitimate uses of farm assets. Not every talent we draft has to debut for this team -- in fact that's kind of impossible.
Let's say I'm right and Mauricio Dubon is destined for a Starting SS/leadoff hitter gig. Can we give it to him? No, the best we can do is groom him to succeed Brock Holt and we already have Marco Hernandez, who I'm convinced is going to be a very nice backup infielder, waiting in the wings for when Holt moves on. He's excess baggage unless, God forbed, Bogaerts gets seriously hurt.
Now let's say another team likes his numbers, sends a scout, likes that too, and wants Dubon to fill a hole they have at SS with an eye towards developing his potential as a top of the order hitter. Of course in that situation you name a reasonable price for Dubon, who's excess talent for us at the position, and see what you can get in the offer. You don't dither around because trading him for a big league player technically weakens our farm. It's always a legitimate use of the talent you have on a farm, which may or may not be a match for what your big league roster needs at the moment, to improve said roster. Especially when you're a big market and can also plug holes in other ways.