Tanabe is leading the project together with a talented new development team. (miketendo64.com)
Because of all of this extra content added through funds raised, as well as the addition of new development teams to make such a reality (see the «Who» question below), a revision of the release window was necessary. (bloodstainedfanforums.com)
It should also be noted that Metroid Prime 4 is the working title for the game, and it's being led by series producer Kensuke Tanabe and a brand new development team, rather than Retro Studios. (nintendowire.com)