The server interfaces that are affected will either lose connectivity or failover to another fabric extender, depending on if an interface is created as a HA interface. UCS M71KR-E/ UCS M71KR-Q Converged network adapter has the capability to failover Ethernet interfaces if so configured. UCS 82598KR-CI 10 Gigabit Ethernet Adapter does not have this capability.
Fibre Channel interfaces that are pinned to failing fabric extender link will just fail and their HA capability depends purely on the host side multipathing driver. If HA/multipathing is not configured for Ethernet/Fibre Channel then servers connected to the failed link will lose connectivity but the other three links will be working as usual. Remember that no automatic re-pinning will happen. You can manually re-pin the servers using two link topology since three link topology is not supported.
