My uncle died intestate and I'm the court appointed representative. He set up his checking acct POD. He has 3 ex wives. I have all 3 divorce papers giving up ex-wives rights to anything in wills, etc. His only sibling recently died. The bank refuses to say who the POD is. Can they send funds to an ex-wife (or anyone else) without notifying estate?

By setting up the account with a POD, your uncle has already instructed the bank to disburse the funds to. The account bypasses any will or estate.

Does the bank not even have to notify the estate of what they have done? What if they send it to an ex that gave up rights to any inheritance?

The POD designation creates, in effect, a gift upon death. The account isn't an inheritance; it bypasses the estate process, as noted above. Your uncle's POD designation on his account was his private business. The bank has no duty to inform your uncle's estate representative, since the account has nothing to do with the estate.

Ask the attorney who represents the estate to write the bank a letter and ask for the information regarding the DOD balance and the named beneficiary. If the estate is required to file a federal estate tax return, it needs the information. (That which may not be in the probate estate can still be in the taxable estate.)

In any case, the bank is entitled to deliver the funds to the POD beneficiary according to the terms of the account. If for some reason, the beneficiary is not entitled to the funds, then the estate makes its claim against the beneficiary; the bank is not obligated to referee.