Also just thought about this, but exactly how does an Engineer dispenser heal people? Looking at it, there are syrniges of... stuff... in it. Maybe the courier can use it as a crafting bench to make chems and ammo?
If that means you're working on a post, you should wait until I put out my upcoming update, which will be within the next few hours. Otherwise, it would not make sense, given that Roadhog is still 'under'.