The resharding test fixture asserts that the "allowMigrations" field is never set in the config collections entry after resharding is finished. After SERVER-107101, it's possible for an incomplete drop index during critical section to pause the migrations but not complete the step to resume them.

Join the drop index command in the postReshardingFn to ensure migrations are resumed before the post resharding checks run, similar to reshard_timeseries_disallow_writes.js.