Currently the reads that the coordinator sends to donor and recipients to get data used for resharding validations do not attach session/lsid (OSI):

• Delta collector doesn't use OSI when sending commands to get delta counts from donors/recipients (here)
• Getting the document count from recipients after cloning also doesn't attach session info (here)
• Getting document count from donors after cloning doesn't attach OSI.

We should consider attaching OSI to the reads to prevent unnecessary read work on the donor in the case of a failover, and there is a read command from a previous coordinator primary. 

More context in this github thread

Question:

• Does OSI even prevent additional reads? I thought it used retryable write machinery which only prevents duplicate writes.