This ticket came out from a TODO in jstests/sharding/move_chunk_allowMigrations.js
Unfortunately we can't re-enable the assertion on the ShardVersion. In fact in this specific test we are directly invoking the _configsvrSetAllowMigrations from the client, thus the command is executed in the configserver with a Client whose session is marked as `external`.
When the config server use the ARS to tell all the shard to refresh it won't propagate the last config optime because the session in use is an external one. So the shard could possibly refresh using an afterClusterTime that is not inclusive of the latest minor version update.