I had read that too, but he has no proof. On Twitter he even had to retract the statement.
PP has some good inside info at times but he's not always right.
He was convinced that MLB2K was done after 2K12 but then 2K13 came around.
If I had to bet, I'd say that RBI was going to be more arcade than sim.
Still, nobody knows for sure yet.
For all we know, MLB had 2K produce another game last year while they worked on RBI.
The vid of Soriano makes a good case that they've been working on this for a year already. Maybe more.