In this test, we verify that commands that synchronize with the donor shard in order to know to be rejected (collMod, createIndexes, dropIndexes) are indeed rejected. There exists a window after which the coordinator starts resharding and before the donor shard has reshardingFields in its cached metadata (to reject the command).

This window itself is fine, because the MODE_S donor resharding lock synchronizes with the MODE_X locks taken for the conflicting commands. So this issue is test behavior only.

To fix this, the test needs to wait for the donor shard to have written its local metadata document before verifying that commands are blocked.