Thanks for your comments MedRoc, and the link to the FAQ. After reading the content of the Update License Button, I'm of the opinion that it's more relevant for users of the Microsoft Office 365 subscription product, rather than for users like myself who made a one-time, stand-alone purchase of the Microsoft Office for Mac product.
I do not intend to make any add-on purchases or add any Microsoft "entitlements" to my non-subscription Office for Mac products that are on my MacBook Pro and iMac Pro that could trigger a need to update my 2 product licenses.
I do keep my Office for Mac products updated as bug fixes or other issues are resolved and am current with the March 26, 2024 Version 16.83.2 (Build 24032318) release. I plan to stay current in this manner until the Office for Mac 2021 reaches end-of-life status. At that point in time, I'll plan to purchase the next one-time stand-alone Office for Mac product. If the only option at that time is for a subscription-based 365 product, I'll migrate to the equivalent product offered by Apple for the Mac product line.
Lastly, every attempt I've made to go through the "Update License" process steps (as covered in that FAQ) on my 2 Macs has failed with either Error Code 44 or Error Code 29, despite removing and reinstalling the Office for Mac 2021 software, removing and reactivating the license and other time-consuming and extraordinarily frustrating efforts that were recommended by well-meaning Independent advisors on this forum. It's my opinion is that this "Update License" process is irrelevant for Office for Mac one-time purchasers such as myself.
I've now concluded that the primary objective for the introduction of the "Update License" software coding "New Feature" was simply to ensure that users of the Microsoft 365 subscription products were kept honest, continuing to pay to use the 365 products on a contractual and ongoing basis, thereby insuring the MS 365 revenue stream into the future..
FIN