MLB.com says they might have a new re-engineered chat in Gameday available by All-Star break.
From MLB.com’s Gameday blog:
We’ve completely retired the old chat engine for a number of reasons: it was unreliable, could only support a very limited number of concurrent users, was very limited in features and was not integrated with other products.
In its place, we will be rolling out a completely revamped chat service by the All-Star break. However, it will not be a Gameday-only chat; instead, it will be better integrated with MLB.TV, the Fantasy Open and other products, with the goal of creating a more complete and immersive user experience.