Now, Eurogamer is reporting, based on "multiple sources" that Bandai Namco is, indeed, the company taking on the responsibility of the game's development. The game was confirmed as being in development since E3 a year ago, when Nintendo said a "talented new development team" was handling the project. Eurogamer also says the game's lead developer is Bandai Namco Studios Singapore-a studio formed in 2013-in collaboration with Nintendo.
In particular, Press-Start noted how Bandai Namco Studios Singapore staff members had not tried very hard to hide they were working on something exciting. They have robust credits developing and publishing many popular franchises, including the Tales games, Ace Combat, .hack// games, Soul Caliber, Xenosaga, Tekken, Dark Souls, and I could keep going on. Chances are Metroid Prime 4 should have a similar direction with some modern twists to the formula akin to how Nintendo released The Legend of Zelda: Breath of the Wild.
Of course, now that we have some firmer footing and we know that Bandai Namco is indeed working on Metroid, we're suddenly paying much closer attention to the other rumors which surrounded this one.
Eurogamer reports the rumour the game is in development at Bandai Namco has been verified by its sources, although the studio has made no official confirmation on the matter.
For reference, Retro Studios (a subsidiary of Nitnendo that is also handling the Donkey Kong Country series now) handled the original Metroid Prime trilogy. The LinkedIn profile has since been amended and all references to the games have been removed.
In other words, we might see new games by Bandai Namco in the near future that could be something expected or totally out of the field. Metroid fans the world over lost their minds with excitement, not to mention that Nintendo would be releasing Metroid: Samus Returns just a few months later. This isn't a surprise, considering that Namco has collaborated with Nintendo before such as with Super Smash Bros. for 3DS and Wii U, as well as Pokken Tournament.