yea 11m changes is quite a bit at once but, I wouldn't expect a constant change like that. After all, the monorepo itself is a little over 3m lines, 1.37m of it being lang/locale files for every language for its front end, 600k of it is comments, and 1.5m is the rest of it.

Not necessarily. Huge additions without matching deletions often happen during restructurings like vendorizing dependencies, importing external packages, generating bindings, or migrating private repos into a monorepo. In these cases new code canbbe introduced to repository and there will be no corresponding deletions in commit history.

I've did similar restructurings myself, eg. Making automatically generated resources static