However, practically, it's not. Within the modern minivan sector, it'd be a non-starter to have a transmission tunnel when all of your competitors don't have that.
Aside from the Chrysler Pacifica, which does offer a traditional AWD (to this day AFAIK), presumably with the requisite transmission tunnel.
There's also the Toyota Sienna, which gets away with AWD by using an electric motor for the rear wheels. Hopefully this continues to catch on.
However, practically, it's not. Within the modern minivan sector, it'd be a non-starter to have a transmission tunnel when all of your competitors don't have that.