Yuji Naka is not only best known for programming and producing classic Sonic games, but also for heading up titles such as Nights into Dreams, Samba de Amigo and Phantasy Star Online while at Sega. He's recently joined Square Enix.
Naka left Sega in 2006 to start up his own studio, called Probe, which released Let's Tap in 2008 for the Wii.
In the original Japanese release, the game came with a cardboard box that players would tap while playing. The studio also made mobile apps and developed a couple of Digimon games.
— てつ (@tetsu_skytree) January 18, 2018
Yesterday on Twitter, as tipster Sang notes, Naka revealed that he's since joined Square Enix.
Just a quick note to let you know, I joined SQUARE ENIX in January.
I’m joining game development as before, and strive to develop games at SQUARE ENIX.
I aim to develop an enjoyable game, please look forward to it.
— Yuji Naka / 中 裕司 (@nakayuji) January 22, 2018
Prope hasn't tweeted since June 2017, which might not mean anything. The official site's recruiting page says it currently isn't taking applications. The site doesn't have a listed phone number with which to confirm on Prope's status, but Naka still lists the studio's website on his Twitter account.