Don't remember where I heard it, but at some point in the last couple of years I heard they reduced the reporting threshold to $5000.
As for the tellers needing approval - each teller has an individual limit they can accept without approval from a supervisor. It has to do with their experience in banking. The newer the teller, the lower their limit. Large deposits require approval, especially if it's a single check, to verify that it's not a forgery because if it's accepted and access to the funds is granted immediately and it's not a legitimate check, the bank can be out that money. The banking program even has a built-in supervisor override in order to complete the transaction if the withdrawal limit is over the teller's limit.
I've worked for two different banks and they both had those rules in place. For a regular customer with a good balance history, it's not necessary to get approval for the deposit prior to completing the transaction, however. We would have a separate pile of large transactions that the supervisor would go through every so often and approve after the customers had long left.