I don't see that as evidence of double standard, but rather of double (indeed multiple) considerations needed to be taken concurrently. Some things you do for one reason, some things you do for another.

- you index threads as a consideration towards readers
- but you don't seek pre-approval of contributors, as a consideration towards volunteer workload

No double standard; just multiple considerations. This is not a case of the same criterion applied differently, but of two different criteria.