`jstests/change_streams/report_post_batch_resume_token.js` asserts that the postBatchResumeToken equals the resume token of the last event returned in the batch. When replicated fast count is enabled (default on DSC, and via `featureFlagReplicatedFastCount` on ASC), the fast-count store writes additional oplog entries in the background. These advance the change stream's scan position past the last returned event, so the PBRT can be greater than that event's resume token. The existing eqIfNotMongos guard only covers sharded (mongos) streams, not the disagg mongod, so the assertion fails intermittently in the disagg change_streams suites.

Same fix as SERVER-136036, which relaxed these assertions in `report_post_batch_resume_token_mongod.js`, now applied to the shared test.