Is low-mileage a red flag? (non-tacoma)

TL;DR: I need a way to value an 8yo Ford Transit van that only has 8600 miles on it. Are there any problems that crop up with a vehicle that mainly sits instead of being driven? All other things being equal, would super low miles ever be a red flag for you?

My boss has asked me to look into selling our 2015 Transit 350. It's only got 8600 miles, seems to run great, and is in excellent shape. Because of that it's hard to gauge a value because there's not a lot of buying and selling of similar vehicles. Everything low-miles is brand new and everything old is beat to hell with 150k+.

Obviously vehicles are made to be driven, so is there a rule of thumb that says older low-mileage cars need X replaced, buy beware because of X? etc. Or is it NBD because these things are built like tanks and it'll run forever? I'm just trying to gauge what problems and concerns a person might have buying a vehicle like this and if those justify selling it for less, or if I should treat it closer to brand new.

FWIW it was for field trips for a summer camp program so it only got about 1k miles per year, never in the winter, so the frame is totally rust free, seats are excellent, some minor paint chips and small surface rust on the roof, clean title, maintenance history, etc.