Tenant migrations are not expected to be run on servers with ephemeralForTest, and in particular tenant migration tests are expected to fail on ephemeralForTest because the donor has to wait for the write to set the migration state to "committed" and "aborted" to be majority committed but it cannot do that on ephemeralForTest.  waitUntilMajorityOpTime inside TenantMigrationAccessBlocker::_waitForOpTimeToMajorityCommit would keep throwing this error since ephemeral storage engine doesn't have snapshotManager so this while loop would cause tests to hang.