I also upgraded from 139 to 140, but all my add-ons are still there.
First, delete everything in the [Data] folder next to the app in the portable version of Google Chrome. Please save your Google Chrome data beforehand to avoid losing it.
Then restart Google Chrome, log in to your Google Account, and sync your data. Once the sync is complete, all your existing add-ons will automatically load and install in Google Chrome.
While this is definitely good news, you could've simply posted in this thread (and let @ropr and @John T. Haller know of the solution) instead of creating a new one (and cluttering the forum with the same topic)...
The Dark Giganotosaur, the ghastly dinosaur (currently in human form)
"Portable and stealth apps are all that matters to me!"
Windows 10 x64 (with ReviOS) | Knoppix 8.1+ x64 | Linux Mint 20.3 Xfce x64