Do I need to take any additional steps after my agency submitted a TM30 for my new address on a retirement O visa?

After your agency submits the TM30 to immigration, it's advisable to ask them for a copy of the TM30 receipt, as you might need it for your next 90-day reporting. Since you are on a Non-O Retirement Visa, you are not required to do a 90-day report until you have completed 3 months on your first 12-month extension. For your first 90-day report at your new address, having the TM30 receipt will be necessary, and you can report online as long as it's done before the expiration date.