Does this have to be a "called" play? Knowing that the runner on first must get a later start, I think the catcher can see the jump the runner gets at 2B and make the decision. Another thing I noticed and the 1B can watch, Thomas was clearly looking at Abrams not the pitcher which would lead me to believe that he knew Abrams was going to go.
Yes, it does need to be a called play because the infielders need to know who is covering the bag (and which bag to cover). If we're throwing to 3B both MIF should hold their position and play defense...we don't want the MIFs to get out of position for a batted ball if we're not going to throw to 2B for the back side runner. If the runner at 1B isn't being held on by the first baseman (he never will be in a R1 and R2 situation) he should always be glancing at the R2. Even if it's not a steal situation R1 will still have to pick up R2 for BIDs, etc.
