These moves put a dent in the Pirates' starting pitching depth, although the Bucs did get Chris Volstad through waivers, which helps. Richard had a clause in his contract that gave him a window in which the Pirates had to either add him to their roster or let another team have him if they were willing to roster him. Richard will evidently start for the Cubs tomorrow. The Pirates had no place for him on their 25-man; the Cubs do. It's a shame that the Bucs were forced to help a rival, but losing Richard is no big deal in itself, for reasons I outlined earlier this week.
The Taillon news is more unfortunate. He'll now essentially miss the rest of the season -- by the time he's back, the minor-league season will be over, or mostly over. I imagine the Pirates will send him to winter ball at that point. He'll be on the Pirates' radar again next year, but by that point he'll have missed two full years of development. For a top prospect, that's a tough blow to take.