It's literal. The red cross is supposed to mean that it's humanitarian, neutral and carries no weapons.
A big reason for medevac is to free soilders from caring for the wounded, so they can continue firing weapons at you.
Neutral seems like a crazy idea to me. It's a critical part of the offense.
The Geneva convention basically states that whomever the injured is in the care of is charged with giving them adequate care. If that care requires medevac it's going to happen.
The protections accorded the wounded and sick apply to friend and foe alike without distinction
https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN31133-FM_4-0...
https://ihl-databases.icrc.org/customary-ihl/eng/docs/v2_rul...