In the drawings environment it is possible to import a title block from another template file (note I said template, not drawing).
So you’re looking to update your title block, or to swap your title block for a newer one, the good news is that there is a really simple way to do this.
You can import a title block from a template, by using the “Add Sheet” option and choosing a template file that contains the title block you wish to add.
Note that you need to right-click on a sheet in the sheet bar, then choose “Add Sheet” (do not click +).
Browse to your template file and click “OK”, a new sheet will be added to your drawing (you can delete it!), importantly the title blocks (& borders) from this template are now loaded into your drawing.
Choose the title block you would like to see on the drawing.
Here’s a video showing how it’s done in Fusion 360.
Special Thanks: I learned this trick from Guenther Andresen on the Autodesk Forums, see his screencast here
UPDATE 22 July 2021
I made a video to help with troubleshooting this workflow. In some instances, the title block might not come through, this is generally because the F2T template file contains references, or the sheets have been renamed (re-naming them back does not ix the issue). The video below will show you how to easily remove the references.
Apologies for the video quality, it was captured on a remote PC at a lower resolution.