Resharding stores the operational FCV at the start of the operation in its coordinator. However, this only happens when upgrading the FCV as in 8.0 FCV it won't store it.

This leaves open the possibility of an operation starting on 8.0 but committing when the FCV is transitioned to upgrading/downgrading which won't play well with OFCV.

This was fixed in the rest of DDL coordinators via storing an authoritativeness level for the entire DDL in the coordinator document. We should explore doing the same for resharding.