If a bank provides investment services that is a wholly owned subsidiary of that bank, would the deposit accounts held with the bank in the name of the investment services be entitled to FDIC insurance?

Why would they not be? The amount of coverage would be based on the capacity in which the funds are held.

The investment service meets the reg definition of a corporation, which qualifies for the designated coverage amount, but given the Bank is the parent company, I wasn't sure if coverage would still apply.

Are these deposits that of the investment subsidiary or those of their customers. If this is their customer's money, it should be held in a fiduciary capacity.

deposits are the investment subsidiary.

for additional context -- the assets (deposits balances) are backed out when putting the call report together for the Bank.

Well, if these funds are not held in a fiduciary capacity, then they are nothing but assets of the subsidiary and therefor assets of the bank and not really deposit accounts, even though you might hold them in such an account for purely accounting purposes.