Why? The developers of Galaxy 1 (EAD Tokyo 1) hasn't released anything since 2007 except for the OOT 3D collaboration with Grezzo. They have had plenty of time to make the next flagship 3D Mario title.
That's not how the EAD Groups / Producers work. Shimizu and his EAD Group 1 are probably not working on Mario. Heck, Koizumi took most of the designers / programmers of SMG1 over to his Tokyo Group 2 anyway. Shimizu for the most part has a different team. He will be working on something else.
They were all made by EAD Tokyo
EAD Tokyo has two sections. Group 1 and Group 2. Just like EAD Kyoto has 5 sections. Just like SPD has 4 sections. Different teams and producers and directors. They are managers and producers. Then theres a whole bunch of directors under them.
Wait, so they're -formally- delineated as such, as a Group No. 1 and a Group No. 2? You're not misconstruing them as two different teams when, perhaps, they just had different directors?
It's official. Its even printed on business cards, and nintendo's press corporate profiles.
Well, I don't know for sure. But Takao Shimizu was the producer of Galaxy 1 and had nothing to do with either Galaxy 2 or 3D Land. He had to be working on something all this time besides the Zelda collaboration. This is the guy responsible for DK '94, Starfox 64, and Jungle Beat. He is pretty important at EAD.
Well they basically did that DSiWare game (Make your Own DS Guide) for Japan, and produced the Grezzo Zelda 3DS projects. Sometimes the developers stall. It took Sugiyama and EAD Kyoto Group 5 a long time to release a game since his promotion. For all we know Shimizu and Tokyo Group 1 are making a cool game for near launch.