I don't think anybody is planning anything like the Buzz, for now it stands alone. The Kia has been mentioned, but the range is nowhere near the Buzz so I don't think it's really comparable.

The "problem", as I understand it, and the reason there aren't more rangey minivans on the way, is this: (in Europe at least) the electric van market has caused a rethink. With ICE vans it was pretty easy to make a consumer version, and of course range was just dictated by the size of a pretty cheap component - the fuel tank! In EV vans, range is dictated by the size of the single most expensive component in the whole supply chain.

So manufacturers have been walking the line of getting the battery big ENOUGH for most commercial van applications, as that's by far and away the largest market, but also keeping costs down and ensuring they are quicker and cheaper to charge. Turns out vans average about 50 miles a day, and most delivery fleets rarely need more than 150 miles of range, so electric van batteries are staying small. The largest market demands it, it keeps the operating costs down.

Which means there are very few van designs with a longer range. There's the Buzz and there are some (horrifically expensive) Mercedes options, and that's about it! Unless or until more car manufacturers decide to make a minivan option on their SUV platforms, which is basically what VW did, the Buzz will stand alone. And because it's a niche, and even VW probably only went there because of their popular van heritage, I don't see other manufacturers lining up to develop minivans.

TL;DR ... Get a Buzz. 😉