Agree 100% on needing more structure to offline DD, as the 9 inning games in particular had no consequence to them whatsoever and got very grindy very quickly.
My guess would be Moments is replacing those single game missions and instead just jumping you to the moment where you need to be to do the mission (so for Griffey's 2B and a BB, maybe just give you 4 Griffey AB's?) I dunno, something like that, a bit like Critical Situations in franchise.
It looks like they've changed Conquest a bit as well, or added more maps, as the trailer had them dong conquest on a map in the shape of 19.