It’s been suggested a few times here and there. Often in What should we build next?
No announcement from Framework that they are working on one. But it would be an easy thing for them to make. It would just be a thunderbolt 4 hub with slots for the Framework modules.
Someone could DIY even. If you find a thunderbolt 4 hub with ports spaced far enough apart it would be very easy, just 3d print a shell to hold the Framework modules so that they look nice.