I've returned to full-time employment at 8/1/21. As I don't anticipate any self-employed income or expenses now, is it appropriate to keep my Quickbooks Self-Employed / Turbotax Bundle until my 2021 tax return is filed in early 2022?

Welcome to the Community, Bob Little golfer.

You have the option to keep the QuickBooks Self-Employed / Turbo Tax Bundle account until the filing comes.

You can also cancel the account so you don't have to pay for the monthly subscription while waiting and re-subscribe when it's time.

If you choose to cancel the account, I'd suggest exporting the data into Excel and saving it. 

For your references about tax filing, check out these resources. These will provide you with detailed steps on how to complete your tax checklist as well as year-end reports:

QuickBooks Self-Employed annual tax guide.

Get quarterly and annual tax info from QuickBooks Self-Employed.

Keep me posted if you have any other questions about QuickBooks Self-Employed. I'm always up to keep helping. Have a nice day!