This is definitely a real concern, and we're actually exploring the Chrome permissions to see if it's possible to redirect your traffic, without requiring the "Read all data" permission, because you're right, that shouldn't be the norm.
IMO this permission is something that Chrome should explore, along with other fine-grained permissions. It might be worth making a bug report to Chromium so you can link it when people ask why you ask for such broad permissions. I think the bug report should probably mention that Google uses go links :)
It would still be possible to create a permission that makes it so the code that edits a page can't make any network requests (the output would need to be HTML sanitized, including links), and I'd like to see that, but it would be more difficult to design, implement, and communicate to users.