It's Koch actually who came in instead of him. According to Gasparotto, Bora preferred to go for stage hunters, and due to Koch's sprinting abilities, they see a better chance for him to win a stage.
Not sure about who got in for whom. Welsford was also a late cut. In the early line-up Koch, van Poppel, Mullen, Welsford, Martinez, Aleotti, Buchmann and Kämna were named. With Kämna out of course bringing Lipowitz is a no Brainer. getting Schachmann some exposure to GT racing also a good idea and he looks also good today. Could be someone to go for stages as well. With this weak stat list at the Giro maybe Buchmann could have been a good helper or a guy for a 9th or 10th place if Martinez doesn't come through as leader.
With Welsford out I think that would have been the better idea. Gamper won't win you a stage and he is also not important for a sprint leadout.
The Giro team because they have a lot of guys with good form at the moment also at that race where I don't know what there goals are in the next weeks. Wandahl and Adria could be also good for challenging stages. They also look great today.