I am assuming that they have not done a hardware upgrade in the last month or so to add the 40GB NICs to these nodes. That being the case, you are correct. You should apply Node Firmware Package 9.3.5. 10.0.1 does support Gen4/Gen5, but is really meant for Gen6. So right now 9.3.5 would be the best fit for your cluster. When you are ready to add Gen6 hardware to the cluster, plan on doing another node firmware update at that time.