UPS Store employee here.
The contract is between the company you ordered from and UPS--hence, they are the ones that have the authority to contact UPS and ask for a delay. But I wouldn't worry about it because at colleges they do indeed just deliver everything to the mailroom as stated above.
Just to be clear on the entire delivery process...yes, in most cases packages without signature confirmation will be left at the doorstep. Not always, though. If the driver doesn't think it's safe to leave it (say, in an apartment hallway) they will leave a note and make two more delivery attempts. This is because if it is stolen, the driver will be under investigation. They don't care if you need it right now. Really, they don't. If you needed it *today* you should have had it delivered to your work or a UPS Store. (4500 strong, there is most likely one near you.)
Signature confirmation, well, requires a signature. No siggy, no package. After 3 delivery attempts are made it is held at the hub for a few days then returned to sender. And, after the first delivery is made, then the reciepient can have the package rerouted to another address or request that it be held at the hub for pickup.
Hope this helps.