Yes, if a robbery is happening you're supposed to comply. Most banks have a few ways of dealing with that.

You have dye packs that are packs of 20's with packs of dye inside of them they're kept in drawers, when pulled out they deactivate and explode in a certain amount of time. Others have trackers that go off when the pack of money goes through the doors and a sensor on the door sets it off to start tracking you. Then others are just packs with the numbers identifying the bill registereD so if they're used you know it's stolen money.

Then whenever a robbery happens you usually keep the money in two drawers, the top has the 1,5,10,20 and the bottom has the 50,100. So when a robbery happens you're usually told to just give the top drawer unless they state they want both but while you do it you also incorporate whatever method of the three above your bank uses (some use only certain methods depending on how high risk your bank is).

Also you're also told to only set off the alarm once the robber has left so that you avoid the robber being stuck in the bank when the cops show up and now you have a hostage scenario.

All this makes it seem like the bank is okay with having money being taken away which is the case. 1-they have the money insured so if it's stolen they get it back. 2- Tellers are also required to put money in the vault when they reach a certain amount in their drawers, say 7k or so(I don't recall the amount), so at any given time if you rob a bank you'll walk out with say, 1,500-3,000 bucks on average. They prefer that than have a shoot out. And you'll also never walk out of a bank robbery with 100k from a teller line, money is never really there. Heck sometimes there's hardly that much in the vault which is why if you want to withdraw a large amount of money (5-6 figures cash) then you have to put in a request if it's a small branch.

All this is fairly common knowledge to industry folks but not as much to the public.