Well to be fair, even 1942 had infantry only maps, or close to IO anyway, though not indoor.
It did occur to me that DICE may have realized Metro was popular but was not the greatest design.... So maybe they want to make some good indoor maps, which is ok, I don't even mind Metro once in a while.
I still however don't like the idea of an whole dlc designed around this idea though. That's not what BF is about. If anything, dlcs should be well rounded with various map types and the selling point being the overall theme of those maps. Like it used to be.