I was a little surprised at Ober, but the Twins may have seen him as a guy who could have been grabbed by a rebuilding team and stashed in the 'pen for a year.
Rortvedt was the right call, IMHO. He's got some things to iron out as a hitter to become anything more than a defensive backup, but he's ready to receive right now and considering how many rough catching situations there are out there right now, I'm pretty confident a team would have grabbed him because of his skills behind the plate and worried about his hit tool later.
Hard to know if anyone is going to take a flyer on Griffin Jax; he might be MLB-ready...but with no minor league season, who knows? He's probably the only one left on the list that's a major concern. I like Jose Miranda, but MLB roster spots are valuable and I'm just not sure a team is going to want to use one for the entire season on him.