They supposedly still are considering their recruiting page for it is still up (and not Zelda related considering they have an entirely separate page for that).
モノリスソフトのブランドイメージとは異なる意欲的なプロジェクト。アクションゲーム開発経験者を募集しております。
www.monolithsoft.co.jp
Rudimentary deepl translation :
And obviously as a reminder hiring pages and the positions they're looking for never indicates the state of development of related projects as it just means getting more hands on deck instead of actually lacking people capable of already doing the tasks in the existing staff.
Why also Retro still recruiting for MP4 doesn't mean much for how the game is progressing unless people think those devs legitimately don't work if they don't have a specific position filled up in time.