I still don't know why they can't at least tell us which companions are planned.
This isn't really a new feature as much as an alteration of an existing one.
Could it be possible that they've written romance lines for all companions (hypothetically here) and now the project sits, waiting to be approved by some crusted, grey haired old man in a suit? Supposedly they had this done-ish at launch and still now they're unsure? Codswallop and bollocks.