If you read their pitch, Massive Chalice has a separate team from Broken Age. I think inXile are the ones using the team continuity argument. Obviously it's better for the company if fans keep shoveling in money regardless of (lack of) any results, but you have to admit this sets a risky precedent.
It's a fairly similar logic though, isn't it? They have other teams coming off other projects, so rather than leave them idle until Broken Age is finished or going to a publisher for a project, they decided to Kickstart another independent project.
Independent-in-theory though, yeah? I mean, if Broken Age is running over budget (as they've acknowledged is the case), money has to come from somewhere. I don't think it's super unfair to wonder if that's what this is in part about--whether they hope to use these funds while Broken Age is in development and recoup it to fund Massive Chalice when Broken Age ships.