Game File's Stephen Totilo asked a Nintendo rep who the developer of Brothership is now that AlphaDream is out of action, and although they wouldn't reveal this information, apparently "some of the original developers who worked on the franchise are involved".
As noted by VGC, some of the team members who stayed on at Nintendo after AlphaDream folded include the company's former development manager Hiroyuki Kubota (who is now at Monolith Soft), and Mario & Luigi director and producer Yoshihiko Maekawa, who recently supervised the Switch version of Super Mario RPG.
As for when the developer behind the new Mario & Luigi game will be revealed, according to Nintendo's rep, fans will just have to wait and see "the game credits at release". There are noticeably plenty of theories already doing the rounds online.
While Nintendo has recently been rather secretive about the developers behind certain projects recently, it doesn't always go to plan. Earlier this week, official documentation seemingly revealed the Polish company Forever Entertainment is involved in the development of Donkey Kong Country Returns HD for Switch.
