The USPS is in a pinch for vehicles. Their LLVs (the boxy mail truck, Long Life Vehicle) are at end of service life and being extended with costly maintenance. They need to hit alternative fuel targets with the replacements, electric looks like the win for most of the trucks, but they aren't there yet so they keep fixing things.

It seems likely that stopgap vehicles are a reasonable answer. In my suburban area I'm seeing minivans where I used to see LLVs.

There is a nice exposition of LLVs and the electric replacement option here: https://www.greatbusinessschools.org/usps-long-life-vehicle/