Question: are nvme drives backwards compatible?
Answer: So yes, a new NVMe drive should work just fine in any NVMe M. 2 slot. If there was a new version of NVMe at some point, it is very likely that it would still be backwards compatible, just like PCIe V 1 video cards can work in PCIe V 3 slots and vise versa. Yes, but you may not get full performance.