While this issue is open, dependents of google-api-core, google-cloud-core. and google-auth should preserve >1, <3 pins on these packages.
This is to prevent diamond dependency conflicts for users using multiple libraries. A more detailed rationale is provided in this document.
If you believe you need to begin requiring >=2.x.x versions of these libraries, please comment here or reach out before releasing your library.
This issue is currently expected to be closed 3 months (90 days) after all google-* packages have been released with expanded pins (see #10565), however the specific amount of time is under discussion.