Ability to mongorestore to shards with different names

Some users, as part of their upgrade process provision completely new clusters to run alongside the old clusters and direct traffic to both clusters as part of an extended testing phase. The shards in the new cluster need to be named differently for the application to distinguish between old and new. However the data when seeded in the new cluster via mongorestore assumes the same shard names and some manual updating of the metadata is thus required. It would be beneficial in these scenarios if mongorestore could restore data into clusters with different names via perhaps a command line parameter.