I think they mean in terms of a good fit for the values - a coal fired power plant might be a technology that doesn’t fit a solarpunk society.

But this is also a cool opportunity to reexamine older technologies to see if they make more sense in a slower society that prioritizes minimizing or internalizing externalities and consuming fewer inputs (energy and materials) than our current one, or if they could work better with modern computer control, materials science, or other improvements that didn’t exist when they fell out of use.