I thought you were talking about Monolith Soft, which is Nintendo 1st party now. Who knew there were 2 companies called Monolith, (one "... Soft", the other "... Productions")
Anyways, it is possible that they are being absorbed into Warner Bros. as they are starting to make more games. Either that, or Warner Bros. is following the Nintendo model of don't announce anything until you can release in ~6 months.