There's still a way to load it under Chrome 138, but when Chrome 139 lands, that's when MV2 will finally be removed.
https://developer.chrome.com/docs/extensions/develop/migrate...
> Just as before, Enterprises using the ExtensionManifestV2Availability policy will continue to be exempt from any browser changes until at least June 2025. Starting in June, the branch for Chrome 139 will begin, in which support for Manifest V2 extensions will be removed from Chrome. Unlike the previous changes to disable Manifest V2 extensions which gradually rolled out to users, this change will impact all users on Chrome 139 at once. As a result, Chrome 138 is the final version of Chrome to support Manifest V2 extensions (when paired with the ExtensionManifestV2Availability key). You can find the release information about Chrome 138 and 139, include ChromeOS's LTS support, on the Chromium release schedule
In current chromium source, it seems still possible to force manifest v2 extensions with `kAllowLegacyMV2Extensions` feature flag?
https://source.chromium.org/chromium/chromium/src/+/main:chr...
This however is a good time to export any extension preferences, because once it's removed you won't be able to access them.