The Atlas team is considering using replication tags in Atlas to label nodes as "operational" or "warming". When a new node is added, the disk is available immediately, but it's slow. Today we warm it slowly and make the node available immediately. In the future, we want to make the node unavailable for secondary reads until the warming is complete and full performance is achieved. A replica set tag would be used when:

• when customers add a new node on Atlas
• when a node falls off and a new node is added as a replacement.

The affected node would use a special RS tag to indicate it is warming until it is warmed.

 
According to our Docs, changing a replica set tag can trigger a primary step down. While the operation is relatively rare, this could introduce unnecessary elections.
We would like to verify whether the primary step down is likely to occur in the above scenario.