It means "This train will be standing in the station for 10 minutes with the doors wide open so that all the nice cold air can come in and replace the limited amounts of warm air that the half-broken heater was trying to pump out. For schedule adjustment."
And we all know what 'schedule adjustment' means, anyway: the 9:20 train is so late, we're gonna just pretend it was the 9:35 train all along.
Oh, and hey, good luck installing those Charlie Card turnstiles in South Station, guys. The new turnstiles are all being put on one side of the lobby concourse (to the left if you're coming up from the subway platforms.) The regular turnstiles are still on the right. There's gonna be a lot of confused people being redirected all the way across the concourse.
Unrelated PS: Is anybody still playing Puzzle Pirates on the Midnight ocean anymore? Would your crew enjoy the company of a dude dressed all in green with a turban who just happens to be a superstar bilger? I have a sword. And a house and I bought a piece of driftwood for my house.